Protein supplemented frozen dessert compositions

ABSTRACT

Frozen dessert products, which include high protein content modified oilseed material, are described. The modified oilseed material typically includes at least 85 wt. % protein (dry solids basis) and has a relatively high average molecular weight, e.g., at least about 40 wt. % of the material has an apparent molecular weight greater than 300,000 daltons.

RELATED APPLICATION

[0001] This application is a continuation-in-part of application Ser.No. 09/717,923 entitled “Process for Producing Oilseed Proteinproducts,” filed Nov. 21, 2000, which is incorporated by referenceherein.

BACKGROUND

[0002] Modified oilseed materials are used as food additives forenhancing texture and other functional characteristics of various foodproducts as well as a source of protein. The use of modified oilseedmaterials particularly modified soybean materials may be limited in someinstances, however, due to their beany flavor and tan-like color. It isstill unclear exactly which components are responsible for the flavorand color characteristics of oilseeds, though a variety of compounds aresuspected of causing these characteristics. Among these are aliphaticcarbonyls, phenolics, volatile fatty acids and amines, esters andalcohols.

[0003] There are extensive reports of processes used for the isolation,purification and improvement of the nutritional quality and flavor ofoilseed materials, particularly soybean materials. Soybean protein inits native state is unpalatable and has impaired nutritional quality dueto the presence of phytic acid complexes which interfere with mammalianmineral absorption, and the presence of antinutritional factors whichinterfere with protein digestion in mammals. The reported methodsinclude the destruction of the trypsin inhibitors by heat treatment aswell as methods for the removal of phytic acid. A wide variety ofattempts to improve the yield of protein secured as purified isolaterelative to that contained in the soybean raw material have also beendescribed.

[0004] Many processes for improving soy protein flavor involve theapplication of heat, toasting, alcohol extraction and/or enzymemodification. These types of processes often result in substantialprotein denaturation and modification, thereby substantially alteringthe product's functionality. In addition, these processes can promoteinteractions between proteins with lipid and carbohydrate constituentsand their decomposition products. These types of reactions can reducethe utility of soy proteins in food products, especially in those thatrequire highly soluble and functional proteins, as in dairy foods andbeverages.

[0005] Commercial soy protein concentrates, which are defined as soyprotein products having at least 70% by weight protein (dry solids basisor “dsb”), are generally produced by removing soluble sugars, ash andsome minor constituents. The sugars are commonly removed by extractingwith: (1) aqueous alcohol; (2) dilute aqueous acid; or (3) water, afterfirst insolubilizing the protein with moist heating. These processesgenerally produce soy protein products with a distinctive taste andcolor.

[0006] Soy protein isolates are defined as products having at least 90%by weight protein (dsb). Commercial processes for producing soy proteinisolates are generally based on acid precipitation of protein. Thesemethods of producing, typically include (1) extracting the protein fromsoy flakes with water at an alkaline pH and removing solids from theliquid extract; (2) subjecting the liquid extract to isoelectricprecipitation by adjusting the pH of the liquid extract to the point ofminimum protein solubility to obtain the maximum amount of proteinprecipitate; and (3) separating precipitated protein curd fromby-product liquid whey. This type of process, however, still tends toproduce a protein product with a distinctive taste and color.

[0007] A number of examples of processes for producing concentrated soyprotein products using membrane filtration technology have beenreported. Due to a number of factors including cost, efficiency and/orproduct characteristics, however, membrane-based purification approacheshave never experienced widespread adoption as commercial processes.These processes can suffer from one or more disadvantages, such asreduced functional characteristics in the resulting protein productand/or the production of a product which has an “off” flavor and/or anoff-color such as a dark cream to light tan color. Membrane-basedprocesses can also be difficult to operate under commercial productionconditions due to problems associated with bacterial contamination andfouling of the membranes. Bacterial contamination can have undesirableconsequences for the flavor of the product.

SUMMARY

[0008] Frozen dessert compositions which include modified oilseedmaterial with desirable flavor and/or color characteristics derived fromoilseed material, such as defatted soybean white flakes or soybean meal,are described herein. The present frozen dessert products, which includethe modified oilseed material are particularly suitable for use as aprotein source for human and/or animal consumption.

[0009] The present modified oilseed material can be produced by amembrane-based purification process which typically includes anextraction step to solubolize proteinaceous material present in anoilseed material. It may be desirable to conduct the extraction as acontinuous, multistage process, e.g., a countercurrent extraction.

[0010] The modified oilseed material can commonly be produced by aprocess which includes an extraction step to solubilize proteinaceousmaterial present in an oilseed material. The process uses one or moremicroporous membranes to separate and concentrate protein from theextract. It is generally advantageous to use a microporous membranewhich has a filter surface with a relatively low contact angle, e.g., nomore than about 40 degrees. The process commonly utilizes eitherrelatively large pore ultrafiltration membranes (e.g., membranes with amolecular weight cut-off (“MWCO”) of about 25,000 to 500,000) ormicrofiltration membranes with pore sizes up to about 1.5μ. Whenmicrofiltration membranes are employed, those with pore sizes of no morethan about 1.0μ and, more desirably, no more than about 0.5μ areparticularly suitable. Herein, the term “microporous membrane” is usedto refer to ultrafiltration membranes and microfiltration membranescollectively. By employing such relatively large pore microporousmembranes, the membrane filtration operation in the present process canbe carried out using transmembrane pressures of no more than about 100psig, desirably no more than about 50 psig, and more commonly in therange of 10-20 psig.

[0011] The modified oilseed material formed by the present method can beused to produce protein supplemented food products such as frozendessert products. The modified oilseed material can have a variety ofcharacteristics that make it suitable for use as a protein source forincorporation into food products. A suitable modified oilseed materialmay include at least about 85 wt. % (dsb) protein, preferably at leastabout 90 wt. % (dsb) protein, and have one or more of the followingcharacteristics: a MW₅₀ of at least about 200 kDa; at least about 40% ofthe material has an apparent molecular weight of greater than 300 kDa;at least about 40 wt. % of the protein in a 50 mg sample may be soluablein 1.0 mL water at 25° C.; a turbidity factor of no more than about0.95; a 13.5% aqueous solution forms a gel having a breaking strength ofno more than about 25 g; an NSI of at least about 80; at least about1.4% cysteine as a percentage of total protein; a Gardner L value of atleast about 85; a substantially bland taste; a viscosity slope of atleast about 10 cP/min; an EOR of no more than about 0.75 mL; a meltingtemperature of at least about 87° C.; a latent heat of at least about 5joules/g; a ratio of sodium ions to a total amount of sodium, calciumand potassium ions of no more than 0.5; no more than about 7000 mg/kg(dsb) sodium ions; and a bacteria load of no more than about 50,000cfu/g.

[0012] A particularly desirable modified oilseed material formed by thepresent method which may be used to produce a protein supplemented foodproduct may include at least about 85 wt. % (dsb) protein, preferably atleast about 90 wt. % (dsb) protein, and meet one or more of thefollowing criteria: a MW₅₀ of at least about 400 kDa; at least about 60%of the material has an apparent molecular weight of greater than 300kDa; at least about 40 wt. % of the protein in a 50 mg sample may besoluable in 1.0 mL water at 25° C.; a turbidity factor of no more thanabout 0.95; a 13.5% aqueous solution forms a gel having a breakingstrength of no more than about 25 g; an NSI of at least about 80; atleast about 1.5% cysteine as a percentage of total protein; a Gardner Lvalue of at least about 85; a substantially bland taste; a viscosityslope of at least about 50 cP/min; an EOR of no more than about 0.5 mL;a melting temperature of at least about 87° C.; a latent heat of atleast about 5 joules/g; a ratio of sodium ions to a total amount ofsodium, calcium and potassium ions of no more than 0.5; no more thanabout 7000 mg/kg (dsb) sodium ions; and a bacteria load of no more thanabout 50,000 cfu/g.

DETAILED DESCRIPTION

[0013] The modified oilseed material used to supplement the presentfrozen dessert compositions generally has a high protein content as wellbeing light colored and having desirable flavor characteristics. Themodified oilseed material can have a variety of other characteristicsthat make it suitable for use as a protein source for incorporation intofood products for human and/or animal consumption.

[0014] The modified oilseed material can commonly be produced by aprocess which includes an extraction step to solubilize proteinaceousmaterial present in an oilseed material and a subsequent purification ofthe extract using one or more microporous membranes to removecarbohydrates, salts and other non-protein components. Very often, theextract is clarified prior to membrane purification by at least removinga substantial amount of the particulate material present in thesuspension produced by the extraction procedure.

[0015] The process described herein uses one or more microporousmembranes to separate and concentrate protein from an oilseed extract.It is generally advantageous to use a microporous membrane which has afilter surface with a relatively low contact angle, e.g., no more thanabout 40 degrees. Microporous membranes with even lower contact angles,e.g., with filter surfaces having a contact angle of no more than about30 degrees and in some instances of no more than about 15 degrees, areparticularly suitable for use in the present method. The processcommonly utilizes either relatively large pore ultrafiltration membranes(e.g., membranes with a molecular weight cut-off (“MWCO”) of at leastabout 30,000) or microfiltration membranes with pore sizes up to about2μ.

[0016] Source of Oilseed Material

[0017] The starting material employed in the present method generallyincludes material derived from defatted oilseed material, although otherforms of oilseed based material may be employed. The fat may besubstantially removed from dehusked oilseeds by a number of differentmethods, e.g., by simply pressing the dehusked seeds or by extractingthe dehusked seeds with an organic solvent, such as hexane. The defattedoilseed material which is employed in preferred embodiments of thepresent process typically contains no more than about 3 wt. % and,preferably, no more than about 1 wt. % fat. The solvent extractionprocess is typically conducted on dehusked oilseeds that have beenflattened into flakes. The product of such an extraction is referred toas an oilseed “white flake.” For example, soybean white flake isgenerally obtained by pressing dehusked soybeans into a flat flake andremoving a substantial portion of the residual oil content from theflakes by extraction with hexane. The residual solvent can be removedfrom the resulting white flake by a number of methods. In one procedure,the solvent is extracted by passing the oilseed white flake through achamber containing hot solvent vapor. Residual hexane can then beremoved from soybean white flakes by passage through a chambercontaining hexane vapor at a temperature of at least about 75° C. Undersuch conditions, the bulk of the residual hexane is volatilized from theflakes and can subsequently be removed, e.g., via vacuum. The materialproduced by this procedure is referred to as flash desolventized oilseedwhite flake. The flash desolventized oilseed white flake is thentypically ground to produce a granular material (meal). If desired,however, the flash desolventized oilseed white flake may be useddirectly in the present method.

[0018] Another defatted oilseed derived material which is suitable foruse in the present process is derived from material obtained by removingthe hexane from the oilseed white flake by a process referred to astoasting. In this process, the hexane extracted oilseed white flakes arepassed through a chamber containing steam at a temperature of at leastabout 105° C. This causes the solvent in the flakes to volatilize and becarried away with the steam. The resulting product is referred to astoasted oilseed flake. As with flash desolventized oilseed white flake,toasted oilseed flake may be used directly in the present method or maybe ground into a granular material prior to extraction.

[0019] While the desolventized oilseed white flake may be used directlyin the extraction step, more commonly the desolventized flake is groundto a meal prior to being employed as starting material for theextraction. Oilseed meals of this type, such as soybean meal, are usedin a wide variety of other applications and are readily available fromcommercial sources. Other examples of oilseed materials which aresuitable for use in the culture medium include canola meal, sunflowermeal, cottonseed meal, peanut meal, lupin meal and mixtures thereof.Oilseed materials derived from defatted soybean and/or defattedcottonseed are particularly suitable for use in the present method sincesuch materials have a relatively high protein content. It is importantto note that although many of the examples and descriptions herein areapplied to a modified soybean material, the present method and materialshould not be construed to be so limited, and may be applied to othergrains and oilseeds.

[0020] Extraction of Oilseed Material

[0021] The extraction of the protein fraction from oilseed material canbe carried out under a variety of conditions using conventionalequipment. Among the factors which affect the choice of processparameters and equipment are the efficiency of the extraction, effectson the quality of the protein in the extract and minimization of theenvironmental impact of the process. For cost and environmental reasons,one often would like to reduce the volume of water used in the process.The process parameters are also generally selected so as to minimize thedegradation of protein, e.g., via indigenous enzymes and/or chemicalreactions, as well as to avoid substantial bacterial contamination ofthe extract.

[0022] A variety of reactor configurations including stirred tankreactors, fluidized bed reactors, packed bed reactors may be employed inthe extraction step. For example, the entire extraction reaction may beperformed in a single vessel having appropriate mechanisms to controlthe temperature and mixing of the medium. Alternatively, the extractionmay be carried out in multiple stages performed in separate reactionvessels.

[0023] As is common with many processes, the optimization of the variousobjectives typically requires a balancing in the choice of processparameters. For example, in order to avoid substantial chemicaldegradation of the protein, the extraction may be run at a relativelylow temperature, e.g., about 15° C. to 40° C. and preferably about 20°C. to 35° C. Such temperatures, however, can be quite conducive tobacterial growth so that it may be best to minimize extraction timesand/or conduct subsequent process operations at higher temperatures toreduce bacterial growth.

[0024] Alternately, the extraction may be run at slightly highertemperatures, e.g., 50° C. to 60° C., to reduce the chances of bacterialcontamination. While this can reduce bacterial growth, the increasedtemperature can exacerbate potential problems due to chemicaldegradation of proteinaceous material. Thus, as for the extraction runat closer to room temperature, when the extraction is carried out at 50°C. to 60° C., it is generally desirable to complete the extraction asrapidly as possible in order minimize degradation of protein. When theextraction is run at temperatures between about 20° C. and 60° C., ithas generally been found that extraction times of one to two hours aresufficient to allow high recoveries of protein while avoidingsignificant protein degradation and/or bacterial contamination. Whenhigher temperatures are used, e.g., 50° C. to 60° C., it has been foundthat the extraction times of no more than about thirty minutes arecommonly sufficient to allow high recoveries of protein while avoidingsignificant protein degradation and/or bacterial contamination. Use ofhigher temperatures is generally avoided since substantial exposure totemperatures of 60° C. and above can lead to protein solutions whichhave a tendency to gel during processing.

[0025] Although oilseed materials have been extracted under both acidicand basic conditions to obtain their proteinaceous material, the presentmethod typically includes an extraction under basic conditions, e.g.,using an alkaline solution having a pH of about 7.5 to about 10. Veryoften, the extraction is conducted by contacting the oilseed materialwith an aqueous solution containing a set amount of base, such as sodiumhydroxide, potassium hydroxide, ammonium hydroxide and/or calciumhydroxide, and allowing the pH to slowly decrease as the base isneutralized by substances extracted out of the solid oilseed material.The initial amount of base is typically chosen so that at the end of theextraction operation the extract has a desired pH value, e.g., a pHwithin the range of 8.0 to 9.5. Alternately, the pH of the aqueous phasecan be monitored (continuously or at periodic time intervals) during theextraction and base can be added as needed to maintain the pH at adesired value.

[0026] When the extraction is carried out as a single stage operation,the spent oilseed material is generally washed at least once with wateror alkaline solution to recover proteinaceous material which may havebeen entrained in the solids fraction. The washings may either becombined with the main extract for further processing or may be used inthe extraction of a subsequent batch of oilseed material.

[0027] The extraction operation commonly produces a mixture of insolublematerial in an aqueous phase which includes soluble proteinaceousmaterial. The extract may be subjected directly to separation viamembrane filtration. In most cases, however, the extract is firstclarified by removing at least a portion of the particulate matter fromthe mixture to form a clarified extract. Commonly, the clarificationoperation removes a significant portion and, preferably, substantiallyall of the particulate material. Clarification of the extract canenhance the efficiency of the subsequent membrane filtration operationand help avoid fouling problems with the membranes used in thatoperation.

[0028] The clarification can be carried out via filtration and/or arelated process (e.g., centrifugation) commonly employed to removeparticulate materials from the aqueous suspensions. Such processes donot, however, generally remove much of the soluble materials and thusthe solubilized protein remains in the aqueous phase for furtherpurification via membrane filtration. Because of the desire to achieve ahigh overall protein yield, the clarification step typically does notmake use of filtration aids such as flocculants which could adsorbsoluble proteinaceous material.

[0029] One suitable method of conducting the extraction andclarification operations employs a series of extraction tanks anddecanter centrifuges to carry out a multi-stage counter currentextraction process. This type of system permits highly efficientextractions to be carried out with a relatively low water to flakeratio. For example, this type of system can efficiently carry outextractions where the weight ratio of the aqueous extraction solution tothe oilseed material in each phase is in the range of 6:1 to 10:1. Useof low water to flake ratios can enable the production of an oilseedextract which contains a relatively high concentration of dissolvedsolids, e.g., dissolved solids concentrations of 5 wt. % or higher andthe production of extracts with at least about 7 wt. % solids is notuncommon. The use of low water to flake ratios and more concentratedextracts allows the process to be run in a system with lower volumecapacity requirements, thereby decreasing demands on capital costsassociated with the system.

[0030] If the system requirements in a particular instance do notinclude significant restrictions on overall volume, the extractionprocess may be carried using higher water to flake ratios. Whererelatively high water to flake ratios are employed in the extractionoperation, e.g., ratios of 20:1 to 40:1, it may be more convenient tocarry out the extraction in a single stage. While these types of waterto flake ratios will require systems capable of handling larger volumesof fluids (per pound of starting oilseed material), the higher dilutionfactor in the protein extraction can decrease the potential for foulingthe microporous membrane(s) used in the membrane filtration operation.

[0031] Membrane Filtration

[0032] Extract liquor is transferred from the extraction system to amembrane separation system, generally by first introducing clarifiedextract into a membrane feed tank. The extract liquor commonly containsabout 4.0-5.0% soluble protein and about 1.5-2.0% dissolved non-proteinmaterial. One purpose of the microfiltration operation is to separateprotein from non-protein material. This can be accomplished bycirculating the extract liquor through a set of microfiltrationmembranes. Water and the non-protein materials pass through the membraneas permeate while most of the protein is retained in the circulatingstream (“retentate”). The protein-containing retentate is typicallyallowed to concentrate by about a 2.5-3× factor (e.g., concentration of30 gallons of incoming crude extract by a 3× factor produces 10 gallonsof retentate). The concentration factor can be conveniently monitored bymeasure the volume of permeate passing through the membranes. Membraneconcentration of the extract by a 3× factor generally produces aretentate stream with dissolved solids containing at least about 80 wt.% protein (dsb). In order to increase the protein concentration to 90wt. %, two 1:1 diafiltrations are typically carried out. In adiafiltration operation, water is added to the concentrated retentateand then removed through the microporous membranes. This can be carriedout in the manner described above or, in an alternate embodiment of thepresent method, the diafiltration can be carried out at the initialstage of the membrane filtration, e.g., by continuously adding water tothe incoming extract in a feed tank so as to substantially maintain theoriginal volume.

[0033] The membrane filtration operation typically produces a retentatewhich is concentrated by at least a 2.5× factor, i.e., passing a volumeof the extract through the filtration system produces a protein-enrichedretentate having a volume of no more than about 40% of the originalextract volume. The output from the membrane filtration operationgenerally provides a protein-enriched retentate which includes at leastabout 10 wt. % protein, and protein concentrations of 12 to 14 wt. % arereadily attained.

[0034] For environmental and efficiency reasons, it is generallydesirable to recover as much of the water from the membrane permeates aspossible and recycle the recovered water back into the process. Thisdecreases the overall hydraulic demand of the process as well asminimizing the volume of effluent discharged by the process. Typically,the diafiltration permeate is combined with the permeate from theconcentration phase of the membrane filtration. The bulk of the water inthe combined permeate can be recovered by separating the combinedpermeate with a reverse osmosis (“RO”) membrane into an RO retentate andan RO permeate. RO separation can produce a permeate that is essentiallypure water. This can be recycled back into earlier stages of theprocess. For example, the RO permeate can be used in an aqueous solutionfor extracting the oilseed material. The RO permeate can also beutilized in a diafiltration operation by diluting protein-enrichedretentate with an aqueous diluent which includes the RO permeate.

[0035] The present process uses a membrane filtration system with one ormore microporous membranes to separate and concentrate protein from theextract. It is generally advantageous to use a microporous membranewhich has a filter surface with a relatively low contact angle, e.g., nomore than about 40 degrees, as such membranes can provide efficientseparation while exhibiting good resistance to fouling. Microporousmembranes with even lower filter surface contact angles (i.e., surfaceshaving greater hydrophilicity) are particularly suitable for use in thepresent process. Such membranes may have a filter surface with a contactangle of 25 degrees or less and some membranes may have a filter surfacecontact angle of no more than about 10 degrees.

[0036] As used herein, the term “contact angle” refers to contact anglesof surfaces measured using the Sessile Drop Method. This is an opticalcontact angle method used to estimate the wetting property of alocalized region on a surface. The angle between the baseline of a dropof water (applied to a flat membrane surface using a syringe) and thetangent at the drop boundary is measured. An example of a suitableinstrument for measuring contact angles is a model DSA 10 Drop ShapeAnalysis System commercially available from Kruss.

[0037] The membranes should be capable of retaining a high percentage ofthe medium and high molecular weight protein components present in theextract while allowing water and other components to pass through themembrane. The membrane filtration operation commonly utilizes eitherrelatively large pore ultrafiltration membranes (e.g., membranes with amolecular weight cut-off (“MWCO”) of at least about 30,000) ormicrofiltration membranes with pore sizes up to about 1.5μ. Low contactangle microfiltration membranes with MWCOs of 25,000 to 200,000 areparticularly suitable for use in the present process. Particularexamples of suitable microporous membranes in modified PAN membraneswith a filter surface contact angle of no more than about 25 degrees andan MWCO of 30,000 to 100,000. To be useful in commercial versions of theprocess, the membranes should be capable of maintaining substantialpermeation rates, e.g, allowing roughly 1500 to 3000 mL/min to passthrough a membrane module containing circa 12 sq. meters of membranesurface area. By employing such relatively large pore microporousmembranes, the membrane filtration operation can generally be carriedout using membrane back pressures of no more than about 100 psig. Morepreferably the membrane back pressure is no more than about 50 psig andefficient membrane separation has been achieved with back pressures inthe range of 10-20 psig.

[0038] The membrane filtration system is generally configured to run ina cross-flow filtration mode. Because larger particles and debris aretypically removed by the earlier clarification operation, themicroporous membrane tends not to become clogged easily. Inclusion ofthe clarification step upstream in the process tends to result in longermembrane life and higher flux rates through the membrane. The membranefiltration system typically employs one or more interchangeable membranemodules. This allows membrane pore size (or MWCO) and/or membrane typeto be altered as needed and allows easy replacement of fouled membranes.

[0039] Cross-flow filtrations can be run either continuously or in batchmode. Cross-flow membrane filtration can be run in a variety of flowconfigurations. For example, a tubular configuration, in which themembranes are arranged longitudinally in tubes similar to the tubes in ashell and tube heat exchanger, is one common configuration since itallows processing of solutions which include a variety of particlesizes. A number of other conventional cross-flow configurations, e.g.,flat sheet and spiral wound, are known to provide effective membraneseparations while reducing fouling of the membrane. Spiral woundcross-flow membrane systems are particularly suitable for use in thepresent processes, especially where the feed solution containsrelatively little particulate matter, such as a clarified oilseedextract. Spiral wound membrane modules tend to provide highly efficientseparations and permit the design of filtration systems with largemembrane surface areas in a relatively compact space.

[0040] As with the extraction operation, the temperature of theprotein-containing solution during the membrane filtration operation canaffect the chemical state of the protein (e.g., via degradation and/ordenaturation) as well as the amount of bacterial contamination whichoccurs. Lower temperatures tend to minimize chemical degradation of theprotein. However, at lower temperatures bacterial growth can be aproblem and the viscosity of more concentrated protein solutions (e.g.,solutions with at least about 10 wt. % protein) can present processingproblems. The present inventors have found that maintaining theprotein-containing extract at about 55 to 60° C. while conducting themembrane separation can effectively suppress bacterial growth whileminimizing changes in protein functionality due to chemicaldegradation/denaturation. It appears that any substantial exposure tohigher temperatures can cause changes in the protein which can makeconcentrated solutions more prone to gelling, e.g., during a subsequentspray drying operation.

[0041] When the membrane filtration is run as a batch operation, themembranes are generally cleaned in between each run. Typically themembrane system will have been cleaned and sanitized the day before arun and the membranes will be stored in a sodium hypochlorite solution.Before use, the membrane system the hypochlorite solution is thendrained out of the membrane system and the entire system is rinsed withwater. When the membrane separation is carried out as a continuousoperation, the membranes are commonly shut down at periodic intervalsand cleaned in a similar fashion.

[0042] A variety of methods are known for cleaning and sanitizingmicroporous membrane systems during ongoing use. One suitable cleaningprocedure includes sequentially flushing the membrane with a series ofbasic, acidic and sanitizing solutions. Examples of suitable sanitizingsolutions include sodium hypochlorite solutions, peroxide solutions, andsurfactant-based aqueous sanitizing solution. Typically, the membrane isrinsed with water between treatments with the various cleaningsolutions. For example, it has been found that membranes with a lowcontact angle filtering surface (e.g., modified PAN microporousmembranes) can be effectively cleaned by being flushed with thefollowing sequence of solutions:

[0043] 1) Water;

[0044] 2) Caustic solution (e.g., 0.2 wt. % NaOH solution);

[0045] 3) Water;

[0046] 4) Mild acid solution (e.g., aqueous solution with a pH 5.5-6);

[0047] 5) Surfactant-based aqueous sanitizing solution (Ultra-Clean™;available from Ecolab, St. Paul, Minn.); and

[0048] 6) Water.

[0049] The cleaning sequence is commonly carried out using roomtemperature solutions. If the membrane is significantly fouled, it maybe necessary to carry out one or more of the rinsing steps at anelevated temperature, e.g., by conducting the caustic, acidic and/orsanitizing rinse at a temperature of about 40° C. to 50° C. In someinstances, the effectiveness of the cleaning sequence can be enhanced byusing a more strongly acidic rinse, e.g., by rinsing the membrane with aacidic solution having a pH of about 4 to 5. Other types of solutionscan be used as a sanitizing solution. For example, if the membrane issufficiently chemically inert, an oxidizing solution (e.g., a dilutesolution of NaOCl or a dilute hydrogen peroxide solution) can be used asa sanitizing agent. After the final water rinse in the cleaningsequence, the membrane can be used immediately to effect the membraneseparation of the present process. Alternatively, the membrane can bestored after cleaning. It is common to store the cleaned membrane incontact with a dilute bleach solution and then rinse the membrane againwith water just prior to use.

[0050] By selecting a membrane which can be effectively cleaned (e.g., amembrane with low contact angle filtering surface such as a modified PANmembrane) it is possible to carry out membrane filtration ofconcentrated oilseed protein extracts which produce retentates havingrelatively low bacterial levels. For example, by employing a modifiedPAN membrane and a cleaning procedure similar to that outlined above, itis possible to produce spray dried protein concentrates having a totalbacterial plate count of no more than about 300,000 cfu/g and,desirably, no more than about 50,000 cfu/g without subjecting theretentate to pasteurization (e.g., via HTST treatment).

[0051] Downstream Processing of Retentate

[0052] The retentate produced by the membrane filtration operation isoften pasteurized to ensure that microbial activity is minimized. Thepasteurization generally entails raising the internal temperature of theretentate to about 75° C. or above and maintaining that temperature fora sufficient amount of time to kill most of the bacteria present in thesolution, e.g., by holding the solution at 75° C. for about 10-15minutes. The product commonly is pasteurized by subjecting theconcentrated retentate to “HTST” treatment. The HTST treatment can becarried out by pumping the concentrate retentate through a steaminjector where the protein-containing concentrate is mixed with livesteam and can be heated rapidly to about 80-85° C. (circa 180° F.). Theheated concentrate is then typically passed through a hold tube, underpressure, for a relatively short period of time, e.g., 5 to 10 seconds.After the hold tube, the heated retentate can be cooled by passage intoto a vacuum vessel. The evaporation of water from the retentate undervacuum results in flash cooling of the heated solution, allowing thetemperature to be rapidly dropped to the range of 45-50° C. (circa130-140° F.). This type of treatment has been found to be very effectiveat destroying bacteria while avoiding substantial chemical degradationof the protein.

[0053] To improve its storage properties, the modified oilseed productis typically dried such that the product contains no more than about 12wt. % moisture, and preferably, no more than about 8 wt. % moisture,based upon the weight of the final dried product. Depending on thedrying method utilized and the form of the dried product, after dryingthe product may be ground into free-flowing solid particles in order tofacilitate handling and packaging. For example, if the dried, modifiedoilseed product is dried into a cake, it can be ground into a driedpowder, preferably such that at least about 95 wt. % of the material isin the form of particles having a size of no more than about 10 mesh.

[0054] In an alternate process, after pH adjustment to a neutral pH, theliquid retentate may be spray dried to form a dry powdered product. Thespray dried product is preferably dried to a water content of no morethan about 10 wt. % water and, more preferably, about 4-6 wt. % water.The retentate can be spray dried by passing a concentrated solution(e.g., circa 10-15 wt. % solids) of the retentate through a spray dryerwith a dryer inlet temperature of about 160-165° C., a feed pumppressure of about 1500 psig and a discharge air temperature of about90-95° C.

[0055] Before the heating which can occur as part of either the spraydrying or HTST treatment, it is usually advantageous to adjust the pH ofthe sample to about neutral. For example, the pH of the retentate isoften adjusted to between 6.5 to 7.5 and, preferably between 6.7 and 7.2prior to any further treatment which involves heating the sample.Heating the concentrated retentate can alter the molecular weightprofile and consequently the functionality of the product. Compare, forexample, the molecular weight profile of the product of Example 2 whichwas not heat treated with that of the product produced according toExample 1. The heat treated material contains a number of proteins notpresent its heated treated counterpart, the product of Example 1. TheDSC's of these two samples also show a distinct difference. The materialproduced according to Example 2 shows a relatively sharp, symmetricalpeak at about 93° C. The other material which was not heat treated, thatof Example 4, also shows a strong absorption of energy at about 93° C.All of the commercial products show either no absorption peak at all orsmall relatively weak absorption peak at about 82° C. DSC scans of thetwo heat treated products formed by the present method (Examples 1 and3) also only show a relatively weak absorption peak at about 82° C.

[0056] In some instances, it may be advantageous to concentrate theretentate produced by the membrane filtration operation prior to a finalspray drying step. This can be accomplished using conventionalevaporative techniques, generally with the aid of vacuum to avoidextensive heating of the processed soy protein material. Where aconcentration step of this type is included in the process, it normallyoccurs after the pH of the retentate has been adjusted to a neutral pH(e.g., a pH of roughly 6.8-7.0).

[0057] Characteristics of Modified Oilseed Material

[0058] The modified oilseed material can be derived from a variety ofprecursor oilseed materials, such as soybean meal, canola meal,sunflower meal, cottonseed meal, peanut meal, lupin meal or mixturesthereof. Soy bean flake or meal are particularly suitable sources ofoilseed protein to utilize in the present method. The modified oilseedmaterial can have a variety of characteristics that make it suitable foruse as a protein source for incorporation into foods for human and/oranimal consumption.

[0059] The modified oilseed material can be used to produce proteinsupplemented food products for human consumption. Examples of proteinsupplemented food products include beverages, processed meats, frozendesserts, confectionery products, dairy-type products, saucecompositions, and cereal grain products. The amount of modified oilseedmaterial used to supplement a food product can vary greatly depending onthe particular food product. A typical protein supplemented food productmay have between 0.1 and 10 wt. %. The modified oilseed material may beused to produce additional food products. It is also important to notethat the food products may be grouped into different or additional foodcategories. A specific food product may fall into more than one category(e.g., ice cream may be considered both a frozen dessert and adairy-type product). The food products provided herein are forillustrative purposes only and are not meant to be an exhaustive list.

[0060] Examples of protein supplemented frozen dessert products includeice cream, malts, shakes, popsicles, sorbets, and frozen puddingproducts.

[0061] Consideration of the characteristics of the modified oilseedmaterial is often important in developing a particular proteinsupplemented food product. For example, dispersability can facilitateeasy mixing of the ingredients (whether a dry formulated mix or the dryisolates) into water, ideally leading to a relatively stable homogenoussuspension. Solubility may be desired to reduce the amount ofparticulates that can be found in finished beverages. Suspendability maybe desired to prevent the settling of the insoluble components from thefinished formula upon standing. Generally, a white colored modifiedoilseed material is preferred as tan and brown solutions can bedifficult to color into white (milk-like) or brightly colored(fruit-like) colors. Clarity of modified oilseed material in solutioncan also be an important beverage characteristic. Foaming, althoughusually undesired in beverages as it can complicate mixing, can also bea positive characteristic in some products (e.g., milk shake-likeproducts). Other characteristics that can be important for particularfood compositions include molecular weight, gelling capability,viscosity, emulsion stability fact content and amino acid content.Specific properties according to one or more of these characteristicsmay be advantageous in developing protein supplemented food products.

[0062] The modified oilseed material formed by the present methodtypically includes a high percentage of high molecular weight proteinsand is less contaminated with low molecular weight proteins. A suitablemethod to analyze the content of high molecular weight proteins found inthe material is based on chromatographic data as described in Example16.

[0063] The raw chromatogramic data may be used to calculate a number ofdifferent metrics. One metric is to calculate the molecular weight atwhich 50% of the mass is above and 50% of the mass is below. This firstmetric is not precisely the mean molecular weight, but is closer to aweighted average molecular weight. This is referred to herein by theterm “MW₅₀.” Another metric is to calculate the wt. % of modifiedoilseed material that has an apparent molecular weight that is greaterthan 300 kDa. Yet another metric is to calculate the wt. % of modifiedoilseed material that has an apparent molecular weight that is less than100 kDa. Any one of these three metrics may be used individually tocharacterize the molecular weight of a particular modified oilseedmaterial. Alternatively, combinations of two or more of these metricsmay be used to characterize the molecular weight profile of a modifiedoilseed material.

[0064] Preferably, the modified oilseed material formed by the presentmethod has a MW₅₀ of at least about 200 kDa. More preferably, at leastabout 400 kDa. Modified oilseed material that has a MW₅₀ of at leastabout 600 kDa can be particularly suitable for some applications. As forthe second metric mentioned above, at least about 40% of a suitablemodified oilseed material may have an apparent molecular weight ofgreater than 300 kDa. For some applications, it may be desirable if atleast about 60% of the modified oilseed material has an apparentmolecular weight of greater than 300 kDa. According to the third metricmentioned above, preferably no more than about 40% of the modifiedoilseed material has an apparent molecular weight of less than 100 kDa.For some applications, however, preferably no more than about 35% of themodified oilseed material has an apparent molecular weight of less than100 kDa. A suitable modified oilseed material may meet the preferredvalues of one or more of these three metrics. For example, aparticularly suitable modified oilseed material may have a MW₅₀ of atleast about 200 kDa and at least about 60% of the modified oilseedmaterial has an apparent molecular weight of greater than 300 kDa.Modified oilseed material that has a MW₅₀ at least about 600 kDa and atleast about 60% of the modified oilseed material has an apparentmolecular weight of greater than 300 kDa can be formed by the presentmethod.

[0065] The modified oilseed material formed by the present methodtypically includes a protein fraction with good solubility. For example,modified oilseed material where at least about 40 wt. % of the proteinin a 50 mg sample of the material is soluble in 1.0 mL water at 25° C.can be formed by the present method. Samples in which at least about 50wt. % of the protein is soluble under these conditions are attainable.The solubility of a modified oilseed material can also be described byits NSI as discussed in Example 9.

[0066] In addition to having relatively good solubility, the modifiedoilseed material formed by the present method often has good propertieswith respect to its suspendability in aqueous solutions. For example,the present process can be used to provide modified oilseed materialwhich has good suspendability. One measure of the suspendability of adried oilseed protein product is its “turbidity factor.” As used herein,the “turbidity factor” is defined in terms of the assay described inExample 14. As described in this example, sufficient sample to make a 5wt. % solution is dissolved/dispersed in a 5 wt. % sucrose solution.After standing for about 1 hour at room temperature, an aliquot of theslurry is diluted 10-fold into water and the absorbance at 500 nm wasmeasured. This absorbance measurement at 500 nm (referred to herein asthe “turbidity factor”) is a measure of turbidity with higher absorbancevalues indicating higher turbidity and lower solubility.

[0067] Preferably, the modified oilseed material formed by the presentmethod has an absorbance at 500 nm of no more than about 0.95 in thisassay, i.e., a turbidity factor of no more than about 0.95. Statedotherwise, a dispersion of 0.5 wt. % of the dried oilseed proteinproduct in a 0.5 wt. % aqueous sucrose solution has an absorbance at 500nm of no more than about 0.95 (after standing for about one hour as a 5wt. % solution in a 5 wt. % sucrose solution).

[0068] The present method allows the production of modified oilseedmaterials which have desirable color characteristics. The productsgenerally have a very light color as evidenced by their Gardner Lvalues. For example, the present method allows the preparation ofmodified oilseed materials which have a dry Gardner L value of at leastabout 85. In some instances, e.g., by running the extraction at a weaklyalkaline pH of 8-9 and conducting the initial extraction at a relativelylow temperature (circa 25-35° C.; 75-95° F.), it may be possible toproduce a sample of an oilseed protein isolate which has a Gardner Lvalue (dry) of at least about 88.

[0069] The present method further allows the production of modifiedoilseed material which has desirable flavor characteristics. Anundesirable flavor is often one of the biggest hindrances to the use ofmodified oilseed material in a consumer product. The flavor of modifiedoilseed material, especially modified soy protein, is derived from acomplex mixture of components. For example, bitterness and other offflavors are often caused by the presence of low molecular weightpeptides (400<MW<2000) and volatile compounds. Some of these smallmolecules arise in the oilseed itself and others are bound to themodified oilseed material at various points in the production process.The substantially bland taste which is typical of the modified oilseedmaterials formed by the present method, may be due to fewer smallmolecular weight peptides and volatile compounds.

[0070] For some food related applications the ability of a modifiedoilseed material to form a gel can be an important functionalcharacteristic. In gelling, the protein denatures to form a loosenetwork of protein surrounding and binding a large amount of water. Asused herein, the term “gel strength” refers to the breaking strength ofa 12.5 wt. % aqueous solution of the modified oilseed material aftersetting and equilibrating the gel at refrigerator temperature (circa4-5° C.). Modified oilseed materials formed by the present method mayhave a gel strength of no more than about 25 g.

[0071] The modified oilseed material formed by the present methodtypically demonstrate desirable viscosity properties. A modified oilseedmaterial that provides a thinner solution under one set of parameters isadvantageous in applications like meat injection where thinner solutionscan more easily be injected or massaged into meat products. Typically, amodified oilseed material that does not show thinning upon heating isgenerally preferred. For some applications, it is a desirable propertyto be able to maintain viscosity through heating cycles. The modifiedoilseed material formed by the present method increases viscosity withheating so its hold on water is improving during the early stage ofcooking. In contrast, most commercial samples decrease in viscosityearly in cooking and decrease their hold on the water.

[0072] Upon heating, protein molecules vibrate more vigorously and bindmore water. At some point, the molecules lose their native conformationand become totally exposed to the water. This is called gelatinizationin starch and denaturation in proteins. Further heating can decreaseviscosity as all interactions between molecules are disrupted. Uponcooling, both types of polymers can form networks with high viscosity(called gels). For some food related applications the ability of amodified oilseed material to form a gel can be an important functionalcharacteristic. Rapid viscosity analysis (“RVA”) was developed foranalysis of starchy samples and is generally similar to Braebenderanalysis. Given the analogy between starch and protein systems, one canapply the RVA analysis described in Example 11 to the modified oilseedmaterials formed by the present method.

[0073] According to the method described in Example 11, one can measurethe slope of the viscosity line over the temperature increase from 45°C. to 95° C., herein referred to as the “viscosity slope.” A suitablemodified oilseed material may have a viscosity slope of at least about30. A particularly suitable modified oilseed material may have aviscosity slope of at least about 50. As shown in Table 3, modifiedoilseed materials formed by the present method showed a viscosity slopeof at least about 70.

[0074] For some food related applications the ability of a modifiedoilseed material to form an emulsion can be an important functionalcharacteristic. Oil and water are not miscible and in the absence of amaterial to stabilize the interface between them, the total surface areaof the interface will be minimized. This typically leads to separate oiland water phases. Proteins can stabilize these interfaces by denaturingonto the surface providing a coating to a droplet (whether of oil orwater). The protein can interact with both the oil and the water and, ineffect, insulate each from the other. Large molecular weight proteinsare believed to be more able to denature onto such a droplet surface andprovide greater stability than small proteins and thereby preventdroplet coalescence.

[0075] Emulsion stability may be determined based according to theprocedure described in Example 12. According to this procedure, a sampleis analyzed according to the amount of oil released from the emulsion.As used herein, the term “Emulsion Oil Release,” or “EOR” refers to theamount of oil released (in mL) from the emulsion according to theconditions of the assay described in Example 12. Modified oilseedprotein products prepared by the present method commonly form relativelystable emulsions. Typically, in the absence of centrifugationessentially no oil will separate from the emulsions within 2-3 hours.After the centrifugation procedure described in Example 12, a suitablematerial may have an EOR of no more than about 0.75 mL. Stated otherwiseno more than about 0.75 mL of oil may be released from the emulsion. Aparticularly suitable emulsion may have an EOR of no more than about 0.5mL, and more desirably, no more than about 0.3 mL after centrifugation.

[0076] During the membrane purification operation, while the levels ofsome components of the modified oilseed material are alteredconsiderably, the fat content (measured after acid hydrolysis) in thepresent modified oilseed material remains relatively unchanged. Thus, ifthe oilseed material is substantially made up of material derived fromdefatted soybean flakes, the modified product obtained from the presentprocess typically has a fat content of about 1 to 3 wt. % (dsb). Forexample, processing of defatted oilseed material, such as soybean meal,by the present method can produce a modified oilseed product having aprotein content of 90 wt. % (dsb) or greater with no more than about 3wt. % (dsb) and preferably, no more than about 2 wt. % fat. As usedherein, the term “fat” refers to triacylglycerols and phospholipids.

[0077] The amino acid composition of a modified oilseed material may notonly be important from a nutritional perspective, but it may also be animportant part of determining the functional behavior of the protein.The amino acid content of a modified oilseed material may be determinedby a variety of known methods depending on the particular amino acid inquestion. For example, cysteine may be analyzed after hydrolysis withperformic acid according to known methods. To compare materials withdifferent protein contents, compositions may be recalculated to a 100%protein basis. Typically, one would expect the amino acid composition ofmaterials derived from a common starting material to be very similar.However, direct comparison of the average compositions shows that themodified oilseed materials formed by the present method includes morecysteine (assayed as cystine) than the commercial samples tested. Forexample, a suitable modified oilseed material may include at least about1.35 wt. % cysteine as a percentage of total protein. A particularlysuitable material may include at least about 1.5 wt. % cysteine as apercentage of total protein.

[0078] Cysteine can play an important role in nutrition and is one ofthe 10 essential amino acids. Cysteine may also play a role in thestabilization of the native structure of soy proteins. Ifoxidation-reduction reagents are used to “restructure” soy proteins, thecysteines may be damaged as an unintended consequence. Loss of nativestructure might remove some of the protection of the cysteine, makingdamage to the native structure more likely. As shown in Example 18,commercial materials show a substantial loss of native structure asmeasured by molecular weight and differential scanning calorimetry.

[0079] The modified oilseed material formed by the present method canhave a variety of characteristics that make it suitable for use as aprotein source for incorporation into food products for human and/oranimal consumption. A suitable modified oilseed material may include atleast about 85 wt. % (dsb) protein, preferably at least about 90 wt. %(dsb) protein. A suitable modified oilseed material may also have a MW₅₀of at least about 200 kDa and/or at least about 40% of the material hasan apparent molecular weight of greater than 300 kDa. The modifiedoilseed material may also have one or more of the followingcharacteristics: at least about 40 wt. % of the protein in a 50 mgsample may be soluable in 1.0 mL water at 25° C.; a turbidity factor ofno more than about 0.95; a 13.5% aqueous solution forms a gel having abreaking strength of no more than about 25 g; an NSI of at least about80; at least about 1.4% cysteine as a percentage of total protein; aGardner L value of at least about 85; a substantially bland taste; aviscosity slope of at least about 10 cP/min; an EOR of no more thanabout 0.75 mL; a melting temperature of at least about 87° C.; a latentheat of at least about 5 joules/g; a ratio of sodium ions to a totalamount of sodium, calcium and potassium ions of no more than 0.5; nomore than about 7000 mg/kg (dsb) sodium ions; and a bacteria load of nomore than about 50,000 cfu/g.

[0080] A particularly desirable modified oilseed material formed by thepresent method which may be used to produce a protein supplemented foodproduct may include at least about 85 wt. % (dsb) protein, preferably atleast about 90 wt. % (dsb) protein, and meet one or more of thefollowing criteria: a MW₅₀ of at least about 400 kDa; at least about 60%of the material has an apparent molecular weight of greater than 300kDa; at least about 40 wt. % of the protein in a 50 mg sample may besoluable in 1.0 mL water at 25° C.; a turbidity factor of no more thanabout 0.95; a 13.5% aqueous solution forms a gel having a breakingstrength of no more than about 25 g; an NSI of at least about 80; atleast about 1.5% cysteine as a percentage of total protein; a Gardner Lvalue of at least about 85; a substantially bland taste; a viscosityslope of at least about 50 cP/min; an EOR of no more than about 0.5 mL;a melting temperature of at least about 87° C.; a latent heat of atleast about 5 joules/g; a ratio of sodium ions to a total amount ofsodium, calcium and potassium ions of no more than 0.5; no more thanabout 7000 mg/kg (dsb) sodium ions; and a bacteria load of no more thanabout 50,000 cfu/g.

[0081] The following examples are presented to illustrate the presentinvention and to assist one of ordinary skill in making and using thesame. The examples are not intended in any way to limit the scope of theinvention. Example 1

[0082] Extractions were carried out batchwise in a 50 gallon stainlesssteel tank. This batch size utilized 30 lbs of white flakes and 30gallons of water. This allowed the extract batch to be extracted andcentrifuged in no more than about 2 hours with laboratory scaleequipment. The amount of bacteria growth which occurs during theextraction operation can be minimized by limiting the amount of timeneeded to carry out the extraction and centrifugation operations.

[0083] The extraction tank, centrifuge, centrifuge filter cloth and allutensils were sanitized with hot water and sodium hypochlorite (NaOCl)prior to use. City water (28.8 gal) at 80° F. (27° C.) was introducedinto the extraction tank. After the extraction tank agitator wasstarted, 30 lbs of soy white flakes were introduced into the extractiontank. The pH of the resulting slurry was adjusted by adding a solutionof 92 grams of sodium hydroxide dissolved in 400 mL city water. Theslurry was then stirred at room temperature for 30 minutes. The pH ofthe suspension is recorded at the beginning and end of the extractionprocess. The initial pH of the aqueous phase of the slurry was about9.0. After stirring for 30 minutes, the pH of the extract was typicallyabout 8.4 to 8.5.

[0084] A Sharples basket centrifuge was then started with the bowl setto 1800 rpm. The extracted slurry was manually fed to the centrifuge ata rate of about 0.5 gpm. Clarified extract liquor was collected andtransferred to the microfiltration feed tank. When the centrifuge basketwas full of spent flakes (after approximately 90 lbs of feed slurry),the cake is washed with 4000 ml (circa 9 lbs) of city water. Thecentrifuge was then stopped and the spent flakes were discarded. Afterrinsing the centrifuge and washing the filter cloth, the centrifuge wasrestarted and the extraction sequence repeated until all of the slurryin the extraction tank had been separated. The clarified extractcontained about 4.0-5.0% soluble protein and 1.5-2.0% dissolvednon-protein material and had a pH of about 7.5 to 7.8.

[0085] After about 150 lbs of extract solution was transferred from theextraction system to the membrane feed tank, the extract liquor wasrecirculated at a flow rate of about 9 gpm through a heater system whichbypassed the membranes. The water temperature of the hot water bath inthe heater system was set at 140° F. (60° C.). This is a temperaturewhich had been shown to retard bacteria growth in the clarified extract(see Example 2).

[0086] After all of the extract liquor has been transferred to themembrane feed tank, the extract liquor at 140° F. was recirculated overthe membranes at 15 gpm with the membrane back pressure set at 10 psig.The membrane filtration system contained four modified PAN membraneswith a nominal 50,000 MWCO (MX-50 membranes available from Osmonics,Minnetonka, Minn.) arranged in series. The total filtration surface areaof the array of membranes was about 12 sq. meters.

[0087] The membrane permeate was collected and monitored by weighing theamount of permeate collected. After being weighed, the permeate wasdiscarded. When the amount of permeate collected equaled 67% of originaltotal weight of the clarified extract, the protein in the retentate hadbeen concentrated by a 3× factor, from about 4% to about 12%. During theinitial concentration phase of the membrane filtration, the permeateflux typically varied from an initial rate of about 2600 ml/min to about1500 ml/min during the later stages of the concentration.

[0088] At this point the concentration operation was stopped by closingthe permeate valves and opening the back-pressure valve on the membrane.For the first diafiltration step, 140° F. (60° C.) water was added tothe retentate in the membrane feed tank in an amount equal to the weightof the retentate after the concentration step. In other words,sufficient water (“diafiltration water”) was added to lower the proteinconcentration by a factor of 2× (i.e., the volume of the retentate wasdoubled by the addition of the water). The permeate valves were thenopened and the back-pressure on the membranes was again set to 10 psig.The permeate was collected and weighed before discarding. When theweight of the diafiltration permeate was equal to the weight of thediafiltration water, the first diafiltration was complete. Thediafiltration operation was then repeated a second time. After thesecond diafiltration had been completed, the solids in the retentatenormally contained about 90 to 93% wt protein.

[0089] After the second diafiltration, the retentate from the membranesystem was transferred to a mixing tank. The membrane system was flushedwith 7 gallons of city water to recover additional protein from thesystem. This flush water was combined with the retentate in the mixingtank. Prior to the next operation, the pH of the retentate was adjustedto 6.8 to 7.0 with dilute HCl.

[0090] Following pH adjustment, the retentate was subjected to treatmentat a relatively high temperature for a short time (“HTST”) in order topasteurize the retentate. The HTST step consists of pumping theconcentrate at 1 gpm to a steam injector. In the steam injector, theconcentrate is mixed with live steam and heated instantly to 280° F. Theheated concentrate passes through a hold tube, under pressure, for 5seconds. After the hold tube, the product flows in to a vacuum vesselwhere the product is flash cooled to 130° F. The product is then spraydried. The HTST step is very effective in killing bacteria, eventhermophiles. Total plate counts could be reduced from as high as300,000 cfu/g to around 100 cfu/g after the HTST operation.

[0091] The HTST treated material was then spray dried to yield a soyprotein product which contained circa 90-93 wt. % protein (dry solidsbasis) and had a water content of about 6 wt. %. The spray dried soyprotein product had an average particle size of about 20 microns and hada water content of about 8-9 wt. %.

EXAMPLE 2

[0092] Batches (30 lbs) of soy white flakes were extracted and processedaccording to the procedure in Example 1 except that after pH adjustment(to pH 6.8-7.0) the retenate was not subjected to HTST treatment.Instead, following pH adjustment, the retenate was spray dried using theprocedure described in Example 1 to yield a soy protein product. Thespray dried soy protein product had an average particle size of about 20microns and a total bacterial count of no more than about 50,000 cfu/g.

EXAMPLE 3

[0093] Batches (30 lbs) of soy white flakes were extracted and processedaccording to the procedure described in Example 1. At the beginning ofthe extraction the pH of the resulting slurry was adjusted by adding asolution of 165 grams of sodium hydroxide dissolved in 1,000 mL citywater. The initial pH of the aqueous phase of the slurry was about 9.8and after stirring for 30 minutes, the pH of the extract was about 9.5.After pH adjustment (to pH 6.8-7.0), the retentate was subjected totreatment at a relatively high temperature for a short time (“HTST”) inorder to pasteurize the retentate using the procedure described inExample 1. The HTST treated material was then spray dried using theprocedure described in Example 1 to yield a soy protein product. Thespray dried soy protein product had an average particle size of about 20microns, contained circa 88-89 wt. % protein (dry solids basis) and hada water content of about 8-9 wt. %.

EXAMPLE 4

[0094] Batches (30 lbs) of soy white flakes were extracted and processedaccording to the procedure in Example 1 except that at the beginning ofthe extraction the pH of the resulting slurry was adjusted by adding asolution of 165 grams of sodium hydroxide dissolved in 1,000 mL citywater. The initial pH of the aqueous phase of the slurry was about 9.8and after stirring for 30 minutes, the pH of the extract was about 9.5.Following membrane filtration and pH adjustment, the retentate was spraydried to yield a soy protein product which contained circa 90 wt. %protein (dry solids basis) and had a water content of 8-9 wt. %. Thespray dried soy protein product had an average particle size of about 20microns and a total bacterial count of no more than about 50,000 cfu/g.

EXAMPLE 5

[0095] Extractions were carried out in an 80 gallon agitated stainlesssteel tank. One pound per minute of soy white flakes were mixedcontinuously with 2.4 gpm of city water. Caustic soda (NaOH) was addedto the tank to control the pH in the tank at 8.5. The temperature in thetank was controlled at 130° F. The average extraction retention time of25 min. was maintained by controlling the discharge rate of the tank.Slurry was pumped continuously from the extraction tank to a decantercentrifuge where the slurry was separated into two streams; a proteinrich liquor stream and a spent flake stream.

[0096] The extraction tank, centrifuge and interconnecting piping werecleaned with a 0.75% caustic solution and sanitized with a 500 ppmsodium hypochlorite (NaOCl) solution prior to use.

[0097] Extract liquor was pumped to an A or B Membrane Feed Tank. Theextract liquor contains about 3.0% protein. The A and B Membrane systemsare used to separate the protein from the soluble carbohydrates usingultrafiltration membranes. After about 100 gallons of extract solutionwas transferred from the extraction system to the membrane feed tank,the extract liquor was recirculated at an approximate flow rate of about80 gpm through the membrane system. The temperature of the extractliquor was controlled at 140° F. (60° C.) with an in-line heatexchanger. A total of 300 gallons of extract liquor was transferred to amembrane feed tank.

[0098] After all of the extract liquor has been transferred to themembrane feed tank, the extract liquor held at 140° F. (60° C.) wasrecirculated over the membranes at 80 gpm with the membrane backpressure controlled at 10-20 psig. The membrane filtration systemcontained six modified PAN membranes with a nominal 50,000 MWCO (MX-50membranes available from Osmonics, Minnetonka, Minn.). The totalfiltration surface area of the array of membranes was approximately 1260sq. feet.

[0099] During the initial concentration phase of the membranefiltration, the permeate flux typically varied from an initial rate ofabout 2.5 gpm to about 1.5 gpm during the later stages of theconcentration. During this step the protein was concentrated from 3% toabout 10%.

[0100] After the initial concentration phase, 100 gallons of 140° F.(60° C.) water was added to a Membrane Feed Tank, which dilutes theprotein down to about 3.3%. The protein was then concentrated back up to10% solids. This is called the diafiltration step. Two diafiltrationsteps were used to increase the protein content of the solids, in theconcentrate stream, up to 90% minimum. During this run the permeate fromthe membrane system was discarded.

[0101] After the second diafiltration, the retentate from the membranesystem was transferred to a dryer feed tank. The membrane system wasflushed with 30 gallons of city water to recover additional protein fromthe system. This flush water was combined with the retentate in thedryer feed tank. Prior to the next operation, the pH of the retentatewas adjusted to 6.8 to 7.0 with dilute HCl.

[0102] Following pH adjustment, the retentate was subjected to treatmentat a relatively high temperature for a short time (“HTST”) in order topasteurize the retentate. The HTST step consists of pumping theconcentrate at 2 gpm to a steam injector. In the steam injector, theconcentrate is mixed with live steam and heated instantly to 280° F.(138° C.). The heated concentrate passes through a hold tube, underpressure, for 10 seconds. After the hold tube, the product flows in to avacuum vessel where the product is flash cooled to 130° F. (54° C.). Theproduct is then spray dried. The HTST step is very effective in killingbacteria, even thermophiles. Total plate counts could be reduced from ashigh as 300,000 cfu/g to around 100 cfu/g after the HTST operation.

[0103] The HTST treated material was then spray dried to yield a soyprotein product having an average particle size of about 80 microns,contained circa 90 wt. % protein (dsb) and a water content of about 8-9wt. %.

EXAMPLE 6

[0104] Batches (240 lbs) of soy white flakes were extracted andprocessed according to the procedure in Example 5 except that after pHadjustment (to pH 6.8-7.0) the retentate was not subjected to HTSTtreatment. Instead, following pH adjustment, the retenate was spraydried according to the procedure described in Example 5 to yield a soyprotein product which contained circa 90-93 wt. % protein (dry solidsbasis) and had a water content of about 6 wt. %. The spray dried soyprotein product had an average particle size of about 80 microns and atotal bacterial count of no more than about 50,000 cfu/g.

EXAMPLE 7

[0105] Batches (240 lbs) of soy white flakes were extracted andprocessed according to the procedure described in Example 5 except thatthe pH of the slurry in the extraction tank was controlled at 9.5. As inExample 5, following pH adjustment (to pH 6.8-7.0), the retentate wassubjected to HTST treatment in order to pasteurize the retentate. TheHTST treated material was then spray dried according to the procedure inExample 5 to yield a soy protein product. The spray dried soy proteinproduct had an average particle size of about 80 microns, containedcirca 88-89 wt. % protein (dsb) and had a water content of about 8-9 wt.%.

EXAMPLE 8

[0106] Batches (240 lbs) of soy white flakes were extracted andprocessed according to the procedure described in Example 7 except thatfollowing membrane filtration and pH adjustment, the retentate was notsubjected to HTST treatment. Instead, following pH adjustment, theretenate was spray dried to yield a soy protein product which containedcirca 90 wt. % protein (dry solids basis) and had a water content of 8-9wt. %. The spray dried soy protein product had an average particle sizeof about 80 microns and a total bacterial count of no more than about50,000 cfu/g.

EXAMPLE 9

[0107] Protein Content, NSI, Solubility, F.A.H. and Color Properties ofModified Oilseed Material

[0108] Four soy protein isolate samples were manufactured using theprocedures described in Examples 1-4 and were subjected to a number oftests to characterize the samples. The samples used for testing werecomposites of multiple production runs in a number of cases.

[0109] The four isolate samples were manufactured by extracting soywhite flakes at either pH 8.5 (Ex. 1 and 2) or pH 9.5 (Ex. 3 and 4). Theextracted protein was concentrated and diafiltered using a membranesystem, pH adjusted to 6.8-7.0, then either passed through a HTST system(Ex. 1 and 3) or not (Ex. 2 and 4), and finally spray dried. The samplestested were composites of multiple production runs in a number of cases.

[0110] The four prototypes were assayed for protein content (dsb),nitrogen solubility index (NSI), by the method of AOCS Ba 11-65, proteinsolubility (true solubility) and fat content (by acid hydrolysis, as is—“F.A.H.” by the method of AOAC 922.06) and the results are shown inTable 1. Results for some commercial soy protein isolate samples arealso included for comparison. PTI Supro™ 515 is a commercial soy proteinisolate recommended for use in processed meats. PTI Supro™ 760 is acommercial soy protein isolate recommended for beverage applications. Anumber of commercial samples have much higher fat contents. Whether thisis a result of processing or post-recovery addition of fat is not clear.

[0111] Protein content was analyzed using either the Kjeldahl or Lecoprocedures, or near-infrared (NIR) spectroscopy. Cysteine was analyzedusing standard methodology.

[0112] The level of free amino nitrogen (FAN) was determined using theninhydrin method (see e.g., European Brewery Convention, 1987). Solidsamples of oilseed material were extracted with water. In solution, eachsample was diluted as needed to obtain 1-3 mg/L FAN. The diluted sampleswere reacted with a buffered ninhydrin solution in a boiling water bathfor 16 min. After cooling in a 20° C. water bath for 10-20 min, thesamples were diluted using potassium iodate in a water/ethanol solution.Within 30 min of this treatment, the absorbance at 570 nm was measuredversus a control solution containing water but otherwise treated likethe samples. The FAN level was calculated from a standard line usingglycine at various concentrations as the reference.

[0113] Protein solubility was determined by weighing 50 mg samples ofthe soy products into microfuge tubes. The samples were dispersed in 1.0mL deionized water at room temperature and allowed to stand for onehour. After centrifuging the samples in a benchtop microfuge for 5minutes, 50 μL aliquots of supernatant were diluted with 950 μL ofdeionized water. The resulting solutions were diluted a second time byplacing 5 μL of the diluted supernatant into a glass tube containing 1.0mL deionized water. Bradford reagent (1.0 mL ) was added to the tube andmixed immediately. The absorbance was read at 595 nm after 5 minutes. Astandard curve based on bovine serum albumin was used to calculate theamount of protein in the original supernatants. The % solubility resultsreported in Table 6 were calculated based on an assumed proteinconcentration of 90% in the protein isolates. TABLE 1 Protein Content,NSI, Solubility, Fat Content and Color. Protein* Solubility F.A.H.Sample (%) NSI (%) (%) Color (L) Example 1 90.6 85.1 54.8 1.17 89.1Example 2 89.9 85.8 43.9 1.49 88.1 Example 3 88.6 33.4 13.0 1.35 86.4Example 4 89.9 95.3 58.2 1.67 86.9 PTI Supro ™ 515 91.1 39.6 27.9 — 85.2PTI Supro ™ 760 90.1 31.6 24.0 2.08 86.5 PTI Supro ™ 590 — — 31.5 2.40 —PTI Supro ™ 661 91.2 — 24.8 2.07 — PTI Supro ™ 710 — — 36.3 1.30 —

[0114] One of the most obvious differences between the prototypes, thematerials formed by the present method, and commercial samples is thecolor. The prototypes are much lighter and brighter in color than thecommercial soy isolates. This is illustrated by comparison of thereadings from a Gardner colorimeter on the samples (see Table 1). Ahigher value of “L” indicates a whiter product.

EXAMPLE 10

[0115] Gel Properties of Modified Oilseed Material

[0116] One measure of the ability of soy protein isolates to interactwith water can be seen in gelling tests. In gelling, the proteindenatures to form a loose network of protein surrounding and binding alarge volume of water. A number of gelling measures can be used, butmeasurement of gel strength after setting and equilibrating atrefrigerator temperature was chosen.

[0117] The soy gel determinations were conducted according to thefollowing procedure:

[0118] 1. Weigh 3.5 g soy protein isolate to a 50 mL tripour plasticbeaker.

[0119] 2. Measure out 30 mL phosphate buffer in a graduated cylinder(0.25% NaH₂PO₄ 0.7% NaCl adjusted to pH 5.7 with NaOH).

[0120] 3. Add approximately 10 mL of buffer to soy. Mix with a spatulauntil the buffer is absorbed then add another 10 mL buffer. Continuemixing and adding until all of the buffer is mixed in and the mixture ishomogenous. Insure that all of the soy remains with the tripour.

[0121] 4. Mix on high for 30 seconds with the hand held homogenizer.

[0122] 5. Cover with aluminum foil.

[0123] 6. Cook in 90° C. water bath for 30 minutes minimizing timebefore samples are cooked to prevent settling. Cool in room temp bathfor 30 minutes. Refrigerate overnight.

[0124] 7. Measure gel strength (deformation) by determining resistanceof the 13.5 wt. % soy isolate gel to a penetrating force using a TextureTechnologies Ti2x Texture Analyzer. The ½ inch diameter acrylic cylinderwas mounted on the instrument. The cylinder was centered over thetripour containing the gel. The penetration speed was set for 3 mm/sec.When a resistance of 4 g was reached, the probe was slowed to 2mm/second and data acquisition was started. The probe was allowed topenetrate the gel for 15 mm then withdrawn at 5 mm/sec.

[0125] A traditional pattern of gel compression involves a risingresistance, followed by a break, followed by continuing resistance. Thebreaking strength is one measure of gel strength. Three of theprototypes follow this pattern (see FIG. 2), but one prototype (Example2) shows no break point. Many commercial samples of soy protein isolatealso do not form gels. Some readily separate after cooking, some formnon-breaking pastes and other form weak gels.

[0126] The weakness of the gels formed from the samples preparedaccording to Examples 1-4 is another major observation. The threebreaking prototypes showed break strengths around 20 g. For comparison,a series of gelatin gels made at differing concentrations were run. Thegelatin gel showing comparable break strength (circa 20 g) was at 2% w/w(data not shown). Soy gels at 12-13% w/w can have break strengths of upto about 70 g, equivalent to gelatin gels between 2 and 5% w/w. Insummary, the gel strength of soy isolates is typically low and the fourprototypes described in Examples 4-7 are at the low end of the rangeexpected for soy isolates.

EXAMPLE 11

[0127] Viscosity of Modified Oilseed Material Upon Heating

[0128] Native molecules (in their natural conformation) can impart someviscosity to a suspension simply by absorbing water. Upon heating, themolecules vibrate more vigorously and bind more water. At some point,the molecules lose their native conformation and become totally exposedto the water. This is called gelatinization in starch and denaturationin proteins. Further heating can decrease viscosity as all interactionsbetween molecules are disrupted. Upon cooling, both types of polymerscan form networks with high viscosity (called gels).

[0129] RVA analysis was developed for analysis of starchy samples and isgenerally similar to Brabender analysis. For example, a sample issuspended in water with stirring. The suspension is heated under somecontrolled regime and the viscosity (resistance to stirring) isconstantly measured. The initial viscosity, peak viscosity, viscosityafter cooling and changes in viscosity during transitions (slopes) canall be diagnostic.

[0130] The viscosity determinations were conducted according to thefollowing procedure:

[0131] 1. Determine sample moisture content (% as is).

[0132] 2. Weigh 2 g±0.01 g of soy isolate into a weighing vessel.

[0133] 3. Determine water weight for 12.5% or 15% dry solids accordingto manufacturer's instructions. Weigh the appropriate amount ofdistilled water directly into the RVA canister.

[0134] 4. Immediately prior to the run, pour dry sample into thecanister. Cap with a rubber stopper and vigorously shake the mixture upand down ten times.

[0135] 5. Wipe off residue from stopper back into the canister. Insert apaddle into the canister, using it to scrape down any residue off thecanister walls.

[0136] 6. Load the sample into the RVA and run the appropriatetemperature profile.

[0137] Two of the testing procedures involved the temperature and rpmprofiles shown in Table 2. TABLE 2 Temperature and rpm profiles forstandard RVA method. Elapsed Time Speed (rpm) Temp° C. 0:00:00 960 500:00:10 160 50 0:04:42 160 95 0:07:12 160 95 0:11:00 160 50 0:13:00 16050 Method 2 0:00:00 960 30 0:01:00 320 30 0:04:00 320 80 0:07:00 320 800:08:00 320 85 0:11:00 320 85 0:12:00 320 90 0:15:00 320 90 0:16:00 32095 0:19:00 320 95

[0138] In one experiment, performed according to the temperature and rpmprofile shown as Method 1 in Table 2, a 15% slurry of isolate in waterwas heated to 95° C., held for 2.5 minutes then cooled to 50° C. Thetypical behavior observed for the material formed by the method ofExample 2 is shown in FIG. 10. The typical behavior observed for acommercial sample of Supro™ 515 is shown in FIG. 11. Generally, theviscosity of the prototypes increased upon initial heating. Theviscosity of the commercial samples, however, decreased upon initialheating. Further, the prototypes had very low initial viscosity, whilethe commercial samples either had no viscosity at any point or had avery high initial viscosity and thinned upon heating. Within theprototypes, the samples which had not been subjected to HTST treatmentshowed viscosity development during heating. Samples that had been HTSTtreated had relatively little viscosity buildup. Each of the prototypestested formed gels upon cooling.

[0139] The potential importance of RVA analysis relates to water lossand fat retention from systems during cooking. Increased viscosity canretard the migration of liquids. The viscosity arises from theinteraction between the protein and the water in the system. As morewater becomes bound by the protein, the viscosity of the systemincreases. This is one of the most important forms of water holding andcan be very persistent and stress resistant. The prototype increasesviscosity with heating so its hold on water is improving during theearly stage of cooking. In contrast, most commercial samples decreasedin viscosity early in cooking and decreased their hold on the water.“Free” water would tend to be more available to evaporate or drain fromthe product. Additionally, other potentially fluid components of thesystem (like fat) would be less likely to drain from a system due to theincreased resistance provided by a higher viscosity.

[0140] The data from another experiment, performed according to thetemperature and rpm profile shown as Method 2 in Table 2, allows one tomeasure the slope of the viscosity (in centipoise, “cP”) as a functionof the time or temperature over the range of 43° C. to 95° C., or“viscosity slope” as used herein (the slope was computed from theinitial viscosity (at 43° C.) and the final viscosity (95° C.) withoutregard to viscosities at any pint in between). Results of this analysisare shown in Table 3 for 12.5% slurries of modified oilseed material. Asthe results indicate, only one of the commercial samples have a positiveviscosity slope (in cP/min).

[0141] The data from another experiment, performed according to thetemperature and rpm profile shown as Method 2 in Table 2, allows one tomeasure the change in viscosity (in centipoise, “cP”). As used herein,the viscosity slope is calculated by determining the difference betweenan initial viscosity at 43° C. and a final viscosity at 95° C. anddividing the difference by the time. The viscosity slope is computedfrom the initial viscosity (at 43° C.) and the final viscosity (95° C.)without regard to viscosities at any point in between. Results of thisanalysis are shown in Table 3 for 12.5% slurries of modified oilseedmaterial. As the results indicate, only one of the commercial sampleshave a positive viscosity slope (in cP/min). TABLE 3 Viscosity Slope andInitial Viscosity. Material Viscosity Slope (cP/min) Viscosity at 1 Min(cP) Example 1 3.87 478 Example 2 53.97 296 Example 3 −25.70 1502Example 4 74.33 442 Example 5 7.83 120 Example 6 77.27 56 Example 712.13 151 Example 8 77.23 127 Supro ™ 610 0.20 — Supro ™ 515 −7.30 579Profam ™ 891 −13.23 391 Supro ™ 760 −23.43 633 Profam ™ 982 −25.43 541

[0142] Another measure that can be made is of the “initial viscosity”(the viscosity after 1 min. of mixing at about 30° C.). This comparisonis also reported in Table 3. The material formed by the method describedin Example 3 had an exceptionally high initial viscosity (about 1500cP), but generally the examples had lower initial viscosities than thecommercial samples. The combination of low initial viscosity and anincrease in viscosity upon heating may be an advantage in applicationslike processed meat products where thinner solutions can more easily beinjected or massaged into meat products but can be less likely to loosewater during cooking.

EXAMPLE 12

[0143] Emulsion Stability of Modified Soy Material

[0144] One of the potential functional properties of proteins isstabilization of interfaces, for example the oil-water interface. Oiland water are not miscible and in the absence of a material to stabilizethe interface between them, the total surface area of the interface willbe minimized. This typically leads to separate oil and water phases. Itis widely believed that proteins can stabilize these interfaces.

[0145] An analysis was performed according to the following procedure.Samples of 10 mg were suspended in 13 mL of 50 mM sodium phosphate at pH7.0. After 15-20 minutes of hydration, 7 mL of corn oil was added. Themixture was homogenized for 1 minute at high speed with a handheldpolytron-type homogenizer. A pipette was used to transfer 12 mL of theemulsion phase (avoiding the aqueous phase) to a graduated centrifugetube. The tubes were centrifuged in a clinical centrifuge at full speedfor 30 minutes. The volume of oil released during centrifugation wasrecorded. Oil volume was read from the bottom of the meniscus to the topof the aqueous layer (which was typically flat). In the absence ofcentrifugation, no oil separates from the emulsions within 2-3 hours. Nomeasurement of the aqueous layer or emulsion layer was made.

[0146] The results shown in Table 4 suggest that the prototypes arecapable of stabilizing emulsions much better than the commercialproducts tested. As used herein, the term “Emulsion Oil Release,” or“EOR” refers to the amount of oil (in mL) released from the emulsionaccording to the assay described above. TABLE 4 Emulsion oil releasedafter centrifugation. Sample Producer EOR (mL) Example 6 Cargill 0.20Example 5 Cargill 0.25 Example 7 Cargill 0.25 Example 8 Cargill 0.25Example 1 Cargill 0.35 Example 4 Cargill 0.40 Supro XT10 PTI 0.45 Profam891 ADM 0.45 Example 2 Cargill 0.50 Example 3 Cargill 0.55 FX950 PTI0.60 Supro ™ 670 PTI 0.65 Supro ™ 710 PTI 0.65 FP 940 PTI 1.15 Supro ™425 PTI 1.45 Profam ™ 981 ADM 1.65 Profam ™ 974 ADM 1.93 Supro ™ 661 PTI2.75 Supro ™ 515 PTI 2.77 Supro ™ 590 PTI 2.90 Supro ™ 760 PTI 3.10Supro ™ 500E PTI 3.40 Profam ™ 648 ADM 3.45

[0147] The hypothesis that high molecular weight proteins would be morefunctional under stress was tested by calculating the correlationcoefficients between the emulsion oil released and the molecular weightvalues reported in Table 11. As the results show, oil release wasnegatively correlated with the portion of protein greater than 300 kDAand the weighted average molecular weight MW₅₀. In other words, largeproteins tended to hold the oil better. TABLE 5 Correlation coefficientsbetween molecular weight measures and EOR. EOR Greater than 300 kDaPearson Correlation −.655  Sig. (2-tailed) .001 Less than 100 kDaPearson Correlation .554 Sig. (2-tailed) .007 MW₅₀ Pearson Correlation−.493  Sig. (2-tailed) .020

EXAMPLE 13

[0148] Flavor Attributes of Modified Oilseed Material

[0149] Beverage products generally place some different demands on thephysical properties of protein isolates. Flavor is a much more importantattribute because the protein isolate can be a much larger portion ofthe finished product. This is especially the case with beveragesintended to meet the health claim criteria. Some fortified adultbeverages contain small amounts of isolate with the bulk of the proteinderived from milk products. In order to successfully compete with suchproducts, beverages based on vegetable protein isolates must havecomparable flavor qualities.

[0150] A flavor panel conducted tests on 5% dispersions of the proteinisolates in water. The materials from Examples 1-4 were compared to PTISupro™ 760, an isolate commonly used in beverages. Preparation of thetest solutions allowed a number of observations to be made. Theprototypes did not disperse well, compared to the Supro™ 760 and had tobe mixed in with a Waring blender. Consequently, about 4-times as muchfoaming was observed with the prototypes. The resulting solutions alsohad a different “color” than the commercial product, essentiallyappearing to be darker. The Example 4 product was the darkest.

[0151] Some of the flavor attributes identified by the flavor panel areshown in Table 6. With the exception of the Example 3 product, theprototypes were associated more with grainy flavors than the commercialproduct. This could be a significant advantage in formulating beverages.

[0152] The same five isolates were then formulated into an adultbeverage similar to one sold ready-to-eat in cans. The product formulaonly included soy protein product at 0.7% of the formula (as is). Thetotal formula is about 30% solids, 12% protein (dry basis) and about 18%of the protein present is from the soy isolate. The overall contributionof soy protein to the formula is about 0.6%. Not surprisingly, therewere no observable differences in flavor between the finished products.TABLE 6 Flavor Attributes Total Intensity of Sample Flavor Flavor NotesSupro ™ 760 1 Cardboard, starchy, starchy mouth- feel, sour Example 11.5 Sweet grain, oat-like, sour, wallpaper paste Example 2 1-1.5 Boiledrice, sweet, starchy, starchy mouthfeel Example 3 1-1.5 Wet wool,starchy, starchy mouth- feel, slightly earthy Example 4 0.5 Grainy,grassy-green, dimethylsulfide (like cream corn), rice water

EXAMPLE 14

[0153] Solubility Attributes of Modified Oilseed Material

[0154] Slurries (5% (w/w)) were made up in the presence of 5% (w/w)sucrose in deionized water. The four prototypes were somewhat difficultto wet and had to be mixed with a homogenizer to get uniform slurries.This was not required for the two commercial products. The resultingslurries were allowed to stand for about 1 hour at room temperature,then aliquots were diluted 10-fold into water and the absorbance at 500nm was measured. This absorbance measurement is influenced by turbidityand/or solubility; higher absorbance values indicated lower solubility.The results are shown in Table 7. The observations suggest that three ofthe prototypes were more prone to go into solution than to simply besuspended in the slurry. This could be an advantage in formulatingbeverage products where opacity is not desired. Photos were also takenof the slurries immediately after settling for 16 hours and aftersubsequent remixing. The three prototypes that showed the lowestabsorbance in Table 7 also showed the least settling overnight. While itmay not be apparent from the photos, the slurry derived from the Example3 prototype had a distinctly brownish tint. It was clear from furtherobservation that a lack of particulates tended to make the suspensionslook darker. Upon settling, the upper portion of the slurries made withthe commercial samples darkened. Shaking the slurries made them appearlighter again. TABLE 7 Absorbance of Protein Isolate Slurries in SucroseSolutions. Sample Absorbance (500 nm) Example 2 0.894 Example 1 0.856Example 4 0.581 Example 3 1.294 Supro ™ 760 1.078 Supro ™ 670 1.531

[0155] Samples of the prototypes were also formulated into an adultbeverage. A high-soy protein beverage that would meet the new healthclaim requirements was targeted. The initial formulas were quite simple(see Table 8). Beverages formulated from the prototypes were compared toones based on Supro™ 670 (from Protein Technology Inc.) and Profam™ 974(from Archer Daniels Midland). These were the products recommended bythe respective manufacturers for formulation of beverages of this type.TABLE 8 Formulas for Flavored high-soy beverage mixes. IngredientVanilla-flavored Chocolate-flavored Soy isolate 38.20 32.21 Sugar 57.2948.32 Cocoa — 15.66 Vanilla powder 2.65 2.24 Salt 1.86 1.57 TOTAL 100.00100.00

[0156] Sensory evaluation was performed on the prototype beverages andon comparable beverages made with the commercial products. Dry mix ofchocolate (44.7 g) or vanilla (37.7) were added to 472 g water, mixed ina Waring blender for about 10 seconds to completely mix and evaluated ona scale from one (poor) to five (good). These levels of additionresulted in identical soy protein contents in the finished beverage(6.48 g per 8-ounce serving). Overall ratings of soy-based beveragescontaining prototype and commercial isolates are shown in Table 9. Theratings are the average of scores from 7 panelists. It was noted thatthe flavored beverages based on the prototypes of Examples 1-4 lackedany gritty mouthfeel and that settled less upon standing than thecommercial products. TABLE 9 Flavor Ratings of soy-based beverages.Material Vanilla-flavored Chocolate-flavored Example 1 3.01 3.43 Example2 2.09 3.08 Example 3 2.54 2.26 Example 4 3.03 3.54 Profam ™ 974 2.192.64 Supro ™ 670 2.03 2.41

EXAMPLE 15

[0157] Protein, Fat, Fiber, Moisture, Ash and Fiber Content of ModifiedOilseed Material

[0158] Additional analyses of the compositions of the four prototypesdescribed in Examples 1-4 were analyzed for protein, fat, fiber,moisture, and ash content. The results are shown in Table 10. Theanalyses were conducted using standard AOAC methods. Crude fiberfollowed method AOAC 962.09. Fat (by acid hydrolysis) followed methodAOAC 922.06. Moisture and ash followed method AOAC 930.42/942.05.Protein (Kjeldahl using a 6.25 conversion factor) was conducted usingmethod AOAC991.20.1.

[0159] One of the consequences of protein degradation by enzymes (oracid) is the release of alpha-amines. These amines react with ninhydrinand allow a way to measure the degree of hydrolysis. This method wasapplied to the commercial and prototype isolates with the results shownin Table 10. Though large differences between commercial isolates areevident, there is no systematic difference between the samples ofExamples 1-4 and the commercial samples. Examples of soy proteinproducts with high, medium or low concentrations of FAN were found.TABLE 10 Example 1 Example 2 Example 3 Example 4 Protein* 83.06 81.4079.69 81.17 FAN (mg/g) 0.57 1.09 0.40 2.06 Fat** 2.14 1.48 1.24 1.17Moisture 5.86 8.45 8.09 8.45 Ash 5.65 5.97 6.51 6.18 Fiber 0.15 0.120.27 0.17

EXAMPLE 16

[0160] Molecular Weight Profiles of Modified Oilseed Material

[0161] One indicator of the amount of proteins still present in theirnative structure is their molecular weight profile. For pure proteins,chromatography usually reveals a single symmetric peak. Mixtures ofproteins, as would exist in soy isolate, should generally consist of aseries of symmetric peaks. If processing did not result in breaking upof the protein, a similar profile would be expected to be observed forsoy isolates.

[0162] Samples of soy protein products (25 mg) were suspended in 1 mL of50 mM sodium phosphate-NaOH (pH 6.8). The samples were mixed vigorously(and occasionally sonicated) for a total of 20 minutes. The samples werecentrifuged for 1 minute in a microfuge to settle the insolubles.Supernatant (100 μL) was dilated with solvent (900 μL), filtered througha 0.45 μm syringe filter and 100 μL of the filtered sample was injectedonto the HPLC. The HPLC columns were a tandem set comprising Biorad SEC125 and SEC 250 gel chromatography columns equilibrated with 50 mMsodium phosphate-NaOH (pH 6.8), 0.01% w/v sodium azide. Flow rate wasset at 0.5 mL/min and the elution of proteins was monitored at 280 nm.In addition to the samples of the soy protein products, a sample offresh, clarified extract (pH 8.5) of soy flakes was diluted inequilibration buffer and run to provide an untreated comparison. Inbrief, the vast majority of commercial samples (not shown) show signs ofdegradation, sometimes significant amounts of degradation. The prototypesamples of Examples 1-8, however, showed substantially less evidence ofdegradation.

[0163] Degradation could be accidental or deliberate. Accidentaldegradation could arise from mechanical damage (e.g., high shear orcavitation mixing), acid or alkali hydrolysis during heating steps, orenzymatic hydrolysis at any time during processing. The enzymatichydrolysis could be due to either protein degrading enzymes naturallypresent in the soy or enzymes secreted by contaminating bacteria. Theproteins could also be intentionally degraded in order to improve thefunctional properties of the protein. Partial hydrolysis can improveemulsification or foaming properties of soy proteins. Extensivehydrolysis can improve solubility under acidic conditions.

[0164] Samples of commercial soy isolates were obtained from variouscommercial sources. The collection of the raw molecular weight profiledata is described above. An analysis of this raw chromatographic datathat uses the correlation between elution time and molecular weight wasused. The HPLC gel filtration column was calibrated with a set ofproteins of “known” molecular weight. A calibration curve was generatedand the equation for that calibration determined. The chromatographs forthe samples were then sliced into 30-50 sections and the areas for thoseslices calculated. This was converted into “area percent” by dividingthe slice's area by the total area for the chromatogram (limited to themolecular weight range between about 1000 daltons and the breakthroughmolecular weight). The elution times for each slice were plugged intothe calibration formula and the corresponding molecular weights werecalculated. A plot was then generated comparing the cumulativepercentage of protein detected and the molecular weight.

[0165] The analysis is analogous to that used for particle size analysisin emulsions. For example, one can ask what percentage of the materialis less than 100 kDa. For Supro™ 425, the less than 100 kDa fractioncomprises about 62%, while for the material formed by the methoddescribed in Example 6, this fraction comprises about 30%. Another wayto analyze the chromatographic data is to calculate the molecular weightat which 50% of the mass is above and 50% of the mass is below. This isnot precisely the mean molecular weight, but is closer to a weightedaverage molecular weight. This is referred to herein by the term “MW₅₀.”The MW₅₀ for Supro™ 425 is about 50 kDa, while the MW₅₀ for the materialformed by the method of Example 6 material is about 480 kDa. TABLE 11Molecular Weight Metrics. Product Wt. % > 300 Wt. % < 100 MW₅₀ (kDa)Example 8 73 14 600 Example 5 72 39 520 Example 7 67 23 680 Example 6 6428 480 Example 4 47 33 290 Example 2 44 50 100 Extract 30 60 40 Example1 30 60 40 Example 3 27 59 80 FX940 22.5 59 55 Profam ™ 891 20 50 100Profam ™ 974 20 66 39 Supro ™ 670 20 62 55 Supro ™ 515 18 65 60 Supro ™500E 16 60 68 FXP ™ 950 15 70 6 Supro ™ 610 15 60 85 Supro ™ 590 14 5485 Supro ™ 425 10 65 50 Supro ™ 710 9 76 29 Supro ™ 760 7 67 55 Supro ™661 6 64 70 Profam ™ 981 5 81 28 Profam ™ 648 4 84 11 Profam ™ 982 2.587 25

[0166] The present prototypes (the materials formed by the methodsdescribed in Examples 1-8) have a significantly higher percentage ofhigh molecular weight proteins than the commercial samples. Mostcommercial samples examined had significantly less high molecular weightmaterial than the raw extract

[0167] The possible impacts of higher molecular weight fractions couldcome in a number of areas. One benefit is the reduced presence of bitterpeptides. Hydrolysis of proteins to low molecular weight peptides(400<MW<2000) often results in production of compounds with bitterflavor. One example of this is aspartame, which is associatedexceptional sweetness but also with a bitter aftertaste. The flavor ofsoy protein is derived from a complex mixture of components. Bitternessis one of these off-flavors. The reduced peptide content couldcontribute to a less bitter tasting product.

[0168] A second consequence of high molecular weight could be ininterface stabilization. Though air-water and oil-water interfaces maybe better stabilized initially by lower molecular weight materials,stabilization of these surfaces may depend on larger molecules. It isworth noting that some of the best emulsion stabilization results wereobserved are with the materials made by the methods described inExamples 5-8.

EXAMPLE 17

[0169] DSC Scans of Modified Oilseed Material

[0170] Samples of soy protein products (50 mg) were weighed into asample vial, mixed with 50 μL water and crimped shut. Samples wereplaced in a Perkin-Elmer DSC and heated at 10° C./min from about 30° C.to about 135° C.

[0171] In brief, native soy protein (as represented by a spray driedsample of a crude extract obtained from untoasted, defatted soy flakes)has a maximum energy absorption at about 93° C. with a side peak ofabsorption around 82° C. The 93° C. peak apparently represents the 11Sprotein and the 82° C. peak the 7S protein (see, e.g., Sorgentini etal., J. Ag. Food Chem., 43:2471-2479 (1995)). The data obtained from DSCscans of the protein products of Examples 1-4 as well as for Supro™ 670are summarized in Table 12. The soy protein products from Examples 2 and4 showed large peak energy absorption at about 93° C. The soy proteinproducts from Examples 1 and 3 showed smaller peak energy absorption atabout 82° C. Commercial samples tended to show peaks only around 82° C.and a number of commercial samples show no signs of heat absorption atall, indicating that the protein in the sample was already completelydenatured. No commercial samples showed a peak at 93° C. TABLE 12 DSCAnalysis of Soy Protein Isolates Ex. 1 Ex. 2 Ex. 3 Ex. 4 Supro ™ 670Peak Energy Absorption 82.68° C. 94.28° C. 82.5° C. 92.21° C. 82.53° C.Energy of Absorption (J/g)  0.98  9.24  1.39  8.30  1.37

EXAMPLE 18

[0172] Amino Acid Content of Modified Oilseed Material

[0173] The amino acid composition of a modified oilseed material may notonly be important from a nutritional perspective, but is an importantpart of determining the functional behavior of the protein. The aminoacid content of a modified oilseed material may be determined by avariety of known methods depending on the particular amino acid inquestion. For example, cysteine may be analyzed after hydrolysis withperfomic acid according to known methods. To compare materials withdifferent protein contents, compositions may be recalculated to a 100%protein basis. Typically, the amino acid composition materials derivedfrom a common starting material would be expected to be very similar.Table 13 shows the amount of cysteine as a weight percent of the totalamount of protein in a number of soy protein isolates. As shown in Table13, direct comparison of the average compositions shows that cysteine(assayed as cystine) in the materials formed by the present methodinclude about 17% more cysteine that the commercial sample average.TABLE 13 Cysteine Content Product Cys Example 5 1.56% Example 6 1.46%Example 7 1.46% Example 8 1.42% Supro ™ 760 1.26% Supro ™ 515 1.24%Profam ™ 982 1.28% Profam ™ 891 1.28% Prototype Average 1.48% CommercialAverage 1.27% Ratio - Prototype/Commercial 1.16   

EXAMPLE 19

[0174] Conductivity/Salt Content of Modified Oilseed Material

[0175] Suspension (5% (w/v)-dsb) of samples of soy protein products wereprepared in distilled deionized water. Each suspension was vigorouslymixed without pH adjustment and left standing for 20-60 min at RT. Thesuspension was re-mixed and the conductivity measured. The pH wasadjusted to 7.0 and the conductivity measured again.

[0176] Analyses for sodium, calcium and potassium content of sampleswere carried out using a modification of the EPA 6010B method. In brief,samples were refluxed in nitric acid, cooled, filtered and diluted byinductively coupled plasma spectroscopy-atomic emission spectroscopy.Two samples were analyzed in duplicate, spikes with standard sampleswere used to confirm complete recovery of ions and two samples withexceptionally high sodium contents were reconfirmed by additionalanalysis. All checks indicated that the results were reliable.

[0177] The modified oilseed materials formed by the present methodgenerally have a relatively low amount of sodium ions. This is reflectedin a low ratio of sodium ions as a percentage (on a weight basis) of thetotal of sodium, calcium and potassium ions. Typically, the ratio ofsodium ions to the total of sodium, calcium and potassium ions is nomore than about 0.5:1.0 (i.e., 50%) and, more desirably, no more thanabout 03:1.0 (i.e., 30%). In some instances, it may be possible toproduce modified soy protein materials where the ratio of sodium ions tothe total of sodium, calcium and potassium ions is no more than about0.2:1.0 (i.e., 20%). The method allows the production of modified soyprotein materials with levels of sodium ions of no more than about 7000mg/kg (dsb). By employing deionized water in the extraction and/ordiafiltration steps, it may possible to produce modified soy proteinmaterials with even lower levels of sodium ions, e.g., sodium ion levelsof 5000 mg/kg (dsb) or below.

[0178] Soybeans contain relatively little sodium, but substantialquantities of potassium and calcium. A number of bases may be used inthe processing of soy isolates that could end up as part of the finishedproduct. While sodium hydroxide would be the most common choice, calciumand potassium hydroxides could also be employed. For example, calciumhydroxide might be used to attempt to produce a soy isolate more similarto milk protein. Because the process described in Examples 1-4 tomanufacture the soy protein products has few pH changes and the final pHchange is downward, there was a reasonable chance that lower levels ofsodium would be found, compared to products produced by commercialprocesses. This is confirmed by the results of the analysis, shown inTable 14.

[0179] The material produced in Examples 1-4 have significantly lowersodium content and significantly higher potassium content than thesamples of commercial soy isolates. With two exceptions, the calciumcontent of the samples from Examples 1-4 was much higher than thecommercial samples. Most surprising is the extremely low potassium andcalcium contents of several products (exemplified by Profam™ 974). TABLE14 Supro ™ Profam ™ Ex. 1 Ex. 2 Ex. 3 Ex. 4 760 974 Conductivity(Micromhos) As is pH 1350 1850 2200 1850 1000 1200 pH 7 1810 1850 40502020 2850 1600 Cation Content (mg/kg) Na 4200 6700 5600 5700 12000 13000Ca 4800 5000 5400 4500 3900 390 K 14000 12000 14000 14000 1600 930Na/(Na + Ca + K) 18.3 28.3 22.4 23.6 68.6 90.8

EXAMPLE 20

[0180] Vanilla Flavored Frozen Dessert

[0181] A vanilla flavored frozen dessert containing 3.7 grams of soyprotein per serving (90 grams) and less than detectable soy notes wasprepared from the following ingredients: Ingredients Formula (wt. %)Liquid whole milk 71.72 Granulated sugar 12.74 Low heat Nonfat Dry Milk4.00 Soy protein isolate (Example 5) 4.64 Corn Syrup 5.88 French Vanillaflavor 0.70 Masking agent 0.30 Liquid yellow food color 0.02

[0182] The sugar, dry milk and soy protein isolate (formed according tothe method described in Example 5) were dry blended and slowly added toliquid milk preheated to 130° F. (54° C.) while mixing with a handheldhomogenizer. The remaining ingredients, i.e., corn syrup, flavors andcolor, were mixed with the milk mixture until thoroughly dispersed. Theresulting mixture (“ice cream mix”) was batch-pasteurized at 183° F.(84° C.) and held at this temperature for 3 minutes. The ice cream mixwas frozen in a retail freezer (electric 4 quart).

EXAMPLE 21

[0183] Wildberry Flavored Frozen Dessert

[0184] A “sorbet-like” wildberry soy frozen dessert product containing8.9 grams of soy protein per serving (117 grams) was prepared from thefollowing ingredients: Ingredients Formula (wt. %) Water 51.09 Soyprotein isolate (Example 5) 8.40 Granulated sugar 25.00 Red food color0.32 Purple food color 0.19 Wildberry Juice Concentrate 15.00

[0185] The soy protein isolate (formed according to the method describedin Example 5) was dispersed in water preheated to 145° F. (63° C.) usinga handheld homogenizer. The protein dispersion was allowed to hydratefor 10 minutes. As the product was cooled in an ice bath to 80° F. (27°C.), sugar and colors were dispersed in the mixture. The juiceconcentrate was gradually added to the cooled mixture while mixingvigorously. The pH of the final mix was measured and adjusted to a pH of4.2-4.3 utilizing a 50% citric acid solution. The final mixture wasfrozen using a retail freezer (electric 4 quart).

EXAMPLE 22

[0186] Oatmeal Raisin Frozen Dessert

[0187] An oatmeal raisin flavored frozen dessert containing 6.59 gramsof soy protein per serving (100 grams) and no detectable soy notes wasprepared as follows: Ingredients Formula (wt. %) Liquid whole milk 73.08Granulated sugar 12.74 Soy protein isolate (Example 5) 7.32 Corn syrupsolids 4.41 Oatmeal raisin flavor 0.15 Masking agent 0.30 Raisins 2.00

[0188] The sugar, soy protein isolate (formed according to the methoddescribed in Example 5) and corn syrup solids were dry blended andslowly added to liquid milk preheated to 130° F. (54° C.) while mixingwith a handheld homogenizer. The remaining ingredients, i.e., flavors,masking agent and raisins, were mixed into the liquid blend untilthoroughly dispersed. The resulting mixture (“ice cream mix”) wasbatch-pasteurized at 183° F. (84° C.) and held at this temperature for 3minutes. The ice cream mix was then frozen in a retail freezer (electric4 quart).

[0189] Additional Illustrative Embodiments

[0190] A number of illustrative embodiments of the present proteinsupplemented frozen dessert composition are described below. Theembodiments described are intended to provide illustrative examples ofthe frozen dessert composition and are not intended to limit the scopeof the invention.

[0191] The protein supplemented frozen dessert composition typicallyincludes a modified oilseed material, which includes at least about 85wt. % and, more desirably, at least about 90 wt. % protein on a drysolids basis.

[0192] The frozen dessert composition can include a modified oilseedmaterial which has an MW₅₀ of at least about 200 kDa, where at leastabout 40 wt. % of the protein in a 50 mg sample of the modified oilseedmaterial is soluble in 1.0 mL water at 25° C.

[0193] The frozen dessert composition can include a modified oilseedmaterial which has an MW₅₀ of at least about 200 kDa and a turbidityfactor of no more than about 0.95 at 500 nm.

[0194] The frozen dessert composition can include a modified oilseedmaterial which has an MW₅₀ of at least about 200 kDa and has an NSI ofat least about 80.

[0195] The frozen dessert composition can include a modified oilseedmaterial which has a turbidity factor of no more than about 0.95 at 500nm, where at least about 40 wt. % of the modified oilseed material hasan apparent molecular weight of at least 300 kDa.

[0196] The frozen dessert composition can include a modified oilseedmaterial which has an MW₅₀ of at least 200 kDa and at least 40 wt. % ofthe protein in a 50 mg sample of the modified oilseed material issoluble in 1.0 mL water at 25° C.

[0197] The frozen dessert composition can include a modified oilseedmaterial in which at least about 40 wt. % of the modified oilseedmaterial has an apparent molecular weight of at least 300 kDa; and atleast about 40 wt. % of the protein in a 50 mg sample of the modifiedoilseed material is soluble in 1.0 mL water at 25° C.

[0198] The frozen dessert composition can include a modified oilseedmaterial which has a bacterial load of no more than 50,000 cfu/g and amelting temperature of at least 87° C.

[0199] The frozen dessert composition can include a modified oilseedmaterial which is produced by a process which includes: (a) extractingoilseed material with an aqueous alkaline solution to form a suspensionof particulate matter in an oilseed extract; and (b) passing the extractthrough a filtration system including a microporous membrane to producea permeate and a protein-enriched retentate. The microporous membranecommonly has a filtering surface with a contact angle of no more than 30degrees.

[0200] The frozen dessert composition can include sugar, water and amodified soybean material which generally includes at least about 90 wt.% protein on a dry solids basis. The modified oilseed material can havean MW₅₀ of at least about 400 kDa and at least about 40 wt. % of theprotein in a 50 mg sample of the modified soybean material is soluble in1.0 mL water at 25° C.

[0201] The invention has been described with reference to variousspecific and illustrative embodiments and techniques. However, it shouldbe understood that many variations and modifications may be made whileremaining within the spirit and scope of the invention.

What is claimed is:
 1. A protein supplemented frozen dessert compositioncomprising a modified oilseed material, wherein the modified oilseedmaterial comprises at least 85 wt. % protein on a dry solids basis; andthe modified oilseed material has an MW₅₀ of at least 200 kDa; and atleast 40 wt. % of the protein in a 50 mg sample of the modified oilseedmaterial is soluble in 1.0 mL water at 25° C.
 2. The frozen dessertcomposition of claim 1 wherein said frozen dessert composition is apasteurized frozen dessert composition.
 3. The frozen dessertcomposition of claim 1 wherein said frozen dessert composition has a pHof about 3.5 to 5.0.
 4. The frozen dessert composition of claim 1comprising about 1 to 10 wt. % protein.
 5. The frozen dessertcomposition of claim 1 comprising about 10 to 30 wt. % protein on a drysolids basis.
 6. A protein supplemented frozen dessert compositioncomprising a modified soybean material, sugar, and water; wherein themodified soybean material comprises at least 90 wt. % protein on a drysolids basis; and the modified soybean material has an MW₅₀ of at least400 kDa and at least 40 wt. % of the protein in a 50 mg sample of themodified soybean material is soluble in 1.0 mL water at 25° C.
 7. Aprotein supplemented frozen dessert composition comprising a modifiedoilseed material, wherein the modified oilseed material is produced by aprocess which includes: extracting oilseed material with an aqueousalkaline solution to form a suspension of particulate matter in anoilseed extract; and passing the extract through a filtration systemincluding a microporous membrane to produce a permeate and aprotein-enriched retentate, wherein the microporous membrane has afiltering surface with a contact angle of no more than 30 degrees. 8.The frozen dessert composition of claim 7 wherein the modified oilseedmaterial is produced by a process which includes: extracting soybeanmaterial at 20° C. to 60° C. with an aqueous solution having a pH of 7.5to 10.0 to form a mixture of particulate matter in an alkaline extractsolution; removing at least a portion of the particulate matter from themixture to form a clarified extract; passing the clarified extract at55° C. to 60° C. through a filtration system including a microporousmodified polyacrylonitrile membrane to produce a permeate and aprotein-enriched retentate, wherein the microporous modifiedpolyacrylonitrile membrane has an MWCO of 25,000 to 500,000 and afiltering surface with a contact angle of no more than 30 degrees; anddiafiltering the protein-enriched retentate through the filtrationsystem to produce a protein-containing diafiltration retentate.
 9. Thefrozen dessert composition of claim 8 wherein the modified oilseedmaterial is produced by a process which further includes heating thediafiltration retentate to at least 75° C. for a sufficient time to forma pasteurized retentate.
 10. The frozen dessert composition of claim 8wherein the modified oilseed material is produced by a process whichincludes extracting the soybean material at 20° C. to 60° C. for no morethan one hour with the aqueous solution to form the mixture.
 11. Aprotein supplemented frozen dessert composition comprising a modifiedoilseed material, wherein the modified oilseed material comprises atleast about 85 wt. % protein on a dry solids basis; and the modifiedoilseed material has a bacterial load of no more than 50,000 cfu/g and amelting temperature of at least 87° C.
 12. A protein supplemented frozendessert composition comprising a modified oilseed material, wherein themodified oilseed material comprises at least about 85 wt. % protein on adry solids basis; and the modified oilseed material has an MW₅₀ of atleast about 200 kDa and a turbidity factor of no more than about 0.95 at500 nm.
 13. A protein supplemented frozen dessert composition comprisinga modified oilseed material, wherein the modified oilseed materialcomprises at least about 85 wt. % protein on a dry solids basis; and themodified oilseed material has an MW₅₀ of at least about 200 kDa and hasan NSI of at least about
 80. 14. A protein supplemented frozen dessertcomposition comprising a modified oilseed material, wherein the modifiedoilseed material comprises at least about 85 wt. % protein on a drysolids basis; at least about 40 wt. % of the modified oilseed materialhas an apparent molecular weight of at least 300 kDa; and the modifiedoilseed material has a turbidity factor of no more than about 0.95 at500 nm.
 15. A protein supplemented frozen dessert composition comprisinga modified oilseed material, wherein the modified oilseed materialcomprises at least about 85 wt. % protein on a dry solids basis; themodified oilseed material has an MW₅₀ of at least 200 kDa and at least40 wt. % of the protein in a 50 mg sample of the modified oilseedmaterial is soluble in 1.0 mL water at 25° C.
 16. A protein supplementedfrozen dessert composition comprising a modified oilseed material,wherein the modified oilseed material comprises at least about 85 wt. %protein on a dry solids basis; and the modified oilseed material has abacterial load of no more than 50,000 cfu/g and a melting temperature ofat least 87° C.
 17. A protein supplemented frozen dessert compositioncomprising a modified oilseed material, wherein the modified oilseedmaterial comprises at least about 85 wt. % protein on a dry solidsbasis; at least about 40 wt. % of the modified oilseed material has anapparent molecular weight of at least 300 kDa; and at least about 40 wt.% of the protein in a 50 mg sample of the modified oilseed material issoluble in 1.0 mL water at 25° C.
 18. The frozen dessert composition ofclaim 17 wherein the modified oilseed material has a turbidity factor ofno more than about 0.95 at 500 nm.
 19. The frozen dessert composition ofclaim 17 wherein the modified oilseed material has an NSI of at leastabout
 80. 20. The frozen dessert composition of claim 17 wherein themodified oilseed material is a modified soybean material which includesat least about 90 wt. % protein on a dry solids basis.
 21. The frozendessert composition of claim 17 wherein the modified oilseed materialhas a melting temperature of at least about 87° C.
 22. The frozendessert composition of claim 17 wherein the modified oilseed materialhas an MW₅₀ of at least about 400 kDa.
 23. The frozen dessertcomposition of claim 17 wherein the modified oilseed material includesat least about 1.4 wt. % cysteine as a percentage of total protein. 24.The frozen dessert composition of claim 17 wherein the modified oilseedmaterial is a soy protein isolate having a substantially bland taste.25. The frozen dessert composition of claim 17 wherein the modifiedoilseed material has a dry Gardner L value of at least about
 85. 26. Thefrozen dessert composition of claim 17 the modified oilseed material hasa bacterial load of no more than about 50,000 cfu/g.
 27. The frozendessert composition of claim 17 wherein the modified oilseed materialhas a latent heat of at least about 5 joules/g.
 28. The frozen dessertcomposition of claim 17 wherein the modified oilseed material has aratio of sodium ions to a total amount of sodium, calcium and potassiumions of no more than about 0.5.
 29. The frozen dessert composition ofclaim 17 wherein the modified oilseed material has no more than about7000 mg/kg (dsb) sodium ions.